PROSPECTUS

                               UNOCAL CORPORATION
                        1,016,310 SHARES OF COMMON STOCK

This Prospectus relates to shares of common stock of Unocal Corporation, a
Delaware corporation, which may be offered and resold from time to time by the
selling stockholders listed below (the "Selling Stockholders"). They obtained
the shares through the Unocal Executive Stock Purchase Plan which was approved
by stockholders in 2000.

We anticipate that the Selling Stockholders will offer shares for sale at prices
prevailing on the New York Stock Exchange on the date of sale. We will not
receive any of the proceeds from the sale of the securities covered by this
Prospectus. The Selling Stockholders will pay all selling and other expenses, if
any, associated with any sale of the shares. We will pay all of the expenses of
registration incurred in connection with this offering.

Each Selling Stockholder and any broker executing selling orders on behalf of
them may be deemed an "underwriter" within the meaning of the Securities Act of
1933, as amended, in which event commissions received by such broker may be
deemed to be underwriting commissions under the Securities Act.

Our common stock is traded on the New York Stock Exchange under the symbol
"UCL." On October 16, 2002, the last reported sale price of our common shares
on the NYSE was $29.75 per share.

See "Risk Factors" beginning on page 3 to read about material risks you should
consider before buying shares of Unocal common stock.

Our principal executive offices are located at 2141 Rosecrans Avenue, Suite
4000, El Segundo, California 90245 and our telephone number is (310) 726-7600.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION NOR ANY STATE SECURITIES
COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR PASSED UPON THE
ADEQUACY OR ACCURACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY
IS A CRIMINAL OFFENSE.

You should rely only on the information contained or incorporated by reference
in this Prospectus. We have not authorized anyone else to provide you with
different information. If anyone provides you with different information, you
should not rely on it. The Selling Stockholders are not making an offer to sell
these securities in any jurisdiction where the offer or sale is not permitted.
You should assume that the information appearing in this prospectus or any
documents incorporated by reference is accurate only as of the date on the front
cover of the applicable document or as specifically indicated in the document.
Our business, financial condition, results of operations and business prospects
may have changed since that date.

               The date of this Prospectus is October 17, 2002.





                                TABLE OF CONTENTS


         UNOCAL......................................................       3

         RISK FACTORS................................................       3

         SPECIAL NOTE ON FORWARD-LOOKING STATEMENTS..................      11

         USE OF PROCEEDS.............................................      12

         SELLING STOCKHOLDERS........................................      12

         PLAN OF DISTRIBUTION........................................      14

         LEGAL MATTERS...............................................      14

         EXPERTS.....................................................      15

         WHERE YOU CAN FIND MORE INFORMATION.........................      15

         SIGNATURES..................................................      19

                                       2




                                     UNOCAL

We were incorporated in Delaware in 1983 to operate as the parent company of
Union Oil Company of California ("Union Oil"), which was incorporated in
California in 1890. We conduct substantially all of our operations through Union
Oil and its subsidiaries.

We are one of the world's largest independent oil and gas exploration and
production companies, with principal operations in North America and Asia. We
are also a leading producer of geothermal energy and a provider of electrical
power in Asia. Other activities include ownership in proprietary and common
carrier pipelines, natural gas storage facilities and the marketing and trading
of hydrocarbon commodities.

Our principal executive offices are located at 2141 Rosecrans Avenue, Suite
4000, El Segundo, California 90245, and the telephone number at that address is
(310) 726-7600.

                                  RISK FACTORS

If you purchase our common stock, you will incur financial risk. Our business
activities also are subject to the hazards and risks. Before buying our stock in
this offering, you should carefully consider the material risks described below,
as well as other information contained in this prospectus and the documents
incorporated by reference in this prospectus under the caption "Where You Can
Find More Information." If any of the events described below occur, our
business, financial condition and/or results of operations could be materially
harmed, and you could lose part or all of your investment.

Our Profitability Is Highly Dependent on the Prices of Crude Oil, Natural Gas
and Natural Gas Liquids, Which Have Historically Been Very Volatile.

Our revenues, profitability, cash flow and future rate of growth are highly
dependent on the prices of crude oil, natural gas and natural gas liquids, which
are affected by numerous factors beyond our control. Oil and gas liquids and gas
prices historically have been very volatile. For example, our lower 48 U.S. gas
prices declined significantly in 2001 from the very high levels reached in the
second half of 2000 and early 2001. A significant downward trend in commodity
prices, comparable to the commodity prices experienced in 1998, would have a
material adverse effect on our revenues, profitability and cash flow and could
result in a reduction in the carrying value of our oil and gas properties and
the amounts of our proved oil and gas reserves.

Our Hedging and Speculating Activities May Prevent Us from Benefiting from Price
Increases and May Expose Us to Other Risks.

To the extent that we engage in hedging activities to endeavor to protect
ourselves from price volatility, we may be prevented from realizing the benefits
of price increases above the levels of the hedges. In addition, we engage in
speculative trading in hydrocarbon commodities and derivative instruments in
connection with our risk management activities, which subjects us to additional
risk.

                                       3


Our Drilling Activities May Not Be Productive.

Drilling for oil and gas involves numerous risks, including the risk that we
will not encounter commercially productive oil or gas reservoirs. The costs of
drilling, completing and operating wells are often uncertain and drilling
operations may be curtailed, delayed or canceled as a result of a variety of
factors, including:

o    Unexpected drilling conditions;
o    Pressure or irregularities in formations;
o    Equipment failures or accidents;
o    Fires, explosions, blow-outs and surface cratering;
o    Marine risks such as capsizing, collisions and hurricanes;
o    Adverse weather conditions; and
o    Shortages or delays in the delivery of equipment.

Our future drilling activities may not be successful and, if unsuccessful, this
failure could have an adverse effect on our future results of operations and
financial condition. While all drilling, whether developmental or exploratory,
involves these risks, exploratory drilling involves greater risks of dry holes
or failure to find commercial quantities of hydrocarbons. Because of the
percentage of our capital budget devoted to higher risk exploratory projects, it
is likely that we will continue to experience significant exploration and dry
hole expenses.

As part of our strategy, we explore for oil and gas offshore, sometimes in deep
water and/or at deep drilling depths, where operations are more difficult and
costly than on land or than at shallower depths and in shallower waters.
Deepwater operations may require a significant amount of time between a
discovery and the time that we can produce and market the oil or gas, increasing
both the financial and operational risks involved with these activities.

We May Not Be Insured against All of the Operating Risks to which Our Business
Is Exposed.

Our business is subject to all of the operating risks normally associated with
the exploration for and production of oil and gas, including blowouts, cratering
and fire, any of which could result in damage to, or destruction of, oil and gas
wells or formations or production facilities and other property and injury to
persons. As protection against financial loss resulting from these operating
hazards, we maintain insurance coverage, including certain physical damage,
comprehensive general liability and worker's compensation insurance. However, we
are not fully insured against all risks in our business. The occurrence of a
significant event against which we are not fully insured could have a material
adverse effect on our results of operations and possibly on our financial
position.

                                       4



Material Differences between Estimated and Actual Timing of Critical Events May
Affect Completion of and Commencement of Production from Development Projects.

We are involved in several large development projects, principally offshore. Key
factors that may affect the timing and outcome of such projects include: project
approvals by joint venture partners; timely issuance of permits and licenses by
governmental agencies; manufacturing and delivery schedules of critical
equipment, such as offshore platforms, and commercial arrangements for pipelines
and related equipment to transport and market hydrocarbons. Delays and
differences between estimated and actual timing of critical events may affect
the completion of and commencement of production from projects.

Our Oil and Gas Reserve Data and Future Net Revenue Estimates Are Uncertain.

Estimates of reserves by necessity are projections based on engineering data,
the projection of future rates of production and the timing of future
expenditures. We base the estimates of our proved oil and gas reserves and
projected future net revenues on reserve reports we prepare. The process of
estimating oil and gas reserves requires substantial judgment on the part of the
petroleum engineers, resulting in imprecise determinations, particularly with
respect to new discoveries. Different reserve engineers may make different
estimates of reserve quantities and revenues attributable to those reserves
based on the same data. Future performance that deviates significantly from
reserve reports could have a material adverse effect on our business and
prospects, as well as on the amounts and carrying values of such reserves.

Fluctuations in the prices of oil and natural gas have the effect of
significantly altering reserve estimates, because the economic projections
inherent in the estimates may reduce or increase the quantities of recoverable
reserves. We may not realize the prices our reserve estimates reflect or produce
the estimated volumes during the periods those estimates reflect. Actual future
production, oil and natural gas prices, revenues, taxes, development
expenditures, operating expenses and quantities of recoverable oil and natural
gas reserves most likely will vary from our estimates.

Any downward revision in our estimated quantities of reserves or of the carrying
values of our reserves could have adverse consequences on our financial results,
such as increased depreciation, depletion and amortization charges and/or
impairment charges, which would reduce earnings and stockholders' equity.

If We Fail to Find or Acquire Additional Reserves, Our Reserves and Production
Will Decline Materially from Their Current Levels.

The rate of production from oil and gas properties generally declines as
reserves are depleted. Except to the extent we conduct successful exploration
and development activities or, through engineering studies, identify additional
productive zones or secondary recovery reserves, and/or acquire additional
properties containing proved reserves, our proved reserves will decline
materially as oil and gas is produced. Future oil and gas production is,
therefore, highly dependent on our level of success in finding or acquiring
additional reserves.

                                       5



Our Growth Depends Significantly on Our Ability to Acquire Oil and Gas
Properties on a Profitable Basis.

Acquisitions of producing oil and gas properties have been a key element of
maintaining and growing our reserves and production in recent years,
particularly in North America. The success of any acquisition will depend on a
number of factors, including the ability to estimate accurately the recoverable
volumes of reserves, rates of future production and future net revenues
attainable from reserves and to assess future abandonment and possible future
environmental liabilities.

There are numerous uncertainties inherent in estimating quantities of proved oil
and gas reserves and actual future production rates and associated costs and
potential liabilities with respect to acquired properties. Actual results may
vary substantially from those assumed in the estimates.

Domestic Governmental Risks

Our domestic operations have been, and at times in the future may be, affected
by political developments and by federal, state and local laws and regulations
such as restrictions on production, changes in taxes, royalties and other
amounts payable to governments or governmental agencies, price controls and
environmental protection regulations.

Global Political and Economic Developments May Impact Operations.

Political and economic factors in international markets may have a material
adverse effect on our operations. On an equivalent-barrel basis, approximately
one-half of our oil and gas production in 2001 was outside the United States,
and approximately two-thirds of our proved oil and gas reserves at December 31,
2001, were located outside of the United States. All of our geothermal
operations and reserves are located outside the United States.

There are many risks associated with operations in international markets,
including changes in foreign governmental policies relating to crude oil,
natural gas liquids, natural gas and geothermal steam pricing and taxation,
other political, economic or diplomatic developments, changing political
conditions and international monetary fluctuations. These risks include:

o    Political and economic instability or war;
o    The  possibility  that a foreign  government may seize our property with or
     without compensation;
o    Confiscatory taxation;
o    Litigation arising from our foreign investments or operations;
o    A  foreign   government   attempting  to  renegotiate  or  revoke  existing
     contractual arrangements;
o    Fluctuating currency values and currency controls; and
o    Constrained  natural gas markets dependent on demand in a single or limited
     geographical area.

Actions of the United States government through tax and other legislation,
executive order and commercial restrictions can adversely affect our operating
profitability overseas, as well as in the

                                       6


U.S. The United States government can prevent or restrict us from doing
business in foreign countries. These restrictions and those of foreign
governments have in the past limited our ability to operate in or gain access
to opportunities in various countries.  Various agencies of the United States
and other governments have from time to time imposed restrictions on our
ability to operate in or gain attractive opportunities in various countries.
Actions by both the United States and host governments have affected operations
significantly in the past and will continue to do so in the future.

The Oil and Gas Exploration and Production Industry Is Very Competitive, and
Many of Our Exploration and Production Competitors Have Greater Financial and/or
Other Resources than We Do.

Strong competition exists in all sectors of the oil and gas exploration and
production industry and, in particular, in the exploration for and development
of new reserves. We compete with major integrated and other independent oil and
gas companies for the acquisition of oil and gas leases and other properties,
for the equipment and labor required to develop and operate those properties and
the marketing of oil and natural gas production. Many of our competitors have
financial and other resources substantially greater than those available to us.
As a consequence, we may be at a competitive disadvantage in bidding for
drilling rights. In addition, many of our larger competitors may have a
competitive advantage when responding to factors that affect the demand for oil
and natural gas production, such as changes in worldwide prices and levels of
production, the cost and availability of alternative fuels and the application
of government regulations. We also compete in attracting and retaining
personnel, including geologists, geophysicists, engineers and other specialists.

Environmental Compliance and Remediation Have Resulted in and Could Continue to
Result in Increased Capital Requirements and Operating Costs.

Our operations are subject to numerous laws and regulations relating to the
protection of the environment. We have incurred and will continue to incur
substantial capital, operating and maintenance, and remediation expenditures as
a result of these laws and regulations. Our compliance with amended, new or more
stringent requirements, stricter interpretations of existing requirements or the
future discovery of contamination may require us to make material expenditures
or subject us to liabilities beyond what we currently anticipate. In addition,
any failure by us to comply with existing or future laws could result in civil
or criminal fines and other enforcement action against us.

Our past and present operations and those of companies we have acquired expose
us to civil claims by third parties for alleged liability resulting from
contamination of the environment or personal injuries caused by releases of
hazardous substances.

For example:

o    We are  investigating  or  remediating  contamination  at a large number of
     formerly and currently owned and/or operated sites; and

                                       7



o    We have been identified as a potentially responsible party at several
     Superfund and other multi-party sites where we or our predecessors are
     alleged to have disposed of wastes in the past.

Environmental laws are subject to frequent change and many of them have become
more stringent. In some cases, they can impose liability for the entire cost of
cleanup on any responsible party without regard to negligence or fault and
impose liability on us for the conduct of others or conditions others have
caused, or for our acts that complied with all applicable requirements when we
performed them.

It is not possible for us to estimate reliably the amount and timing of all
future expenditures related to environmental and legal matters and other
contingencies because:

o    Some sites are in the early stages of investigation, and other sites may be
     identified in the future;
o    Cleanup  requirements  are  difficult  to predict at sites  where  remedial
     investigations  have not been  completed or final  decisions  have not been
     made regarding  cleanup  requirements,  technologies  or other factors that
     bear on cleanup costs;
o    Environmental  laws  frequently  impose joint and several  liability on all
     potentially  responsible  parties, and it can be difficult to determine the
     number and financial condition of other potentially responsible parties and
     their shares of responsibility for cleanup costs;
o    Environmental  laws and  regulations are  continually  changing,  and court
     proceedings are inherently uncertain; and
o    Some legal matters are in the early stages of  investigation  or proceeding
     or their  outcomes  otherwise may be difficult to predict,  and other legal
     matters may be identified in the future.

Due to these uncertainties we could be required to provide significant
additional reserves in the future, which would adversely affect our results of
operations and possibly our financial position.

More detailed information with respect to the matters discussed above is set
forth under the caption - "Environmental Regulation" in our amended 2001 Annual
Report on Form 10-K/A, which is incorporated into this prospectus by reference.

Unocal Depends Upon Payments from Its Subsidiaries.

Unocal conducts substantially all of its operations through Union Oil,
65-percent-owned Pure Resources, Inc., and other subsidiaries. Unocal's
principal sources of cash are dividends and advances from its subsidiaries,
investments, payments by subsidiaries for services rendered and interest
payments from subsidiaries on cash advances. The amount of cash and income
available to Unocal from its subsidiaries largely depends upon each subsidiary's
earnings and operating capital requirements. The terms of Pure's borrowing
arrangements and its publicly-held minority interest limit payments and
transfers of funds. In addition, the ability of the subsidiaries to make any
payments or transfer funds will depend on the subsidiaries' earnings, business
and tax considerations and legal restrictions. Failure to receive adequate cash
and income from its subsidiaries could jeopardize Unocal's ability to make
payments on debt securities issued by

                                       8



Unocal, including those held by Unocal Capital Trust, to satisfy Unocal's
guarantees of debt securities of Union Oil and the preferred securities of
Unocal Capital Trust, and to pay dividends on its common stock.

Our Debt Level May Limit Our Financial Flexibility.

As of June 30, 2002, our balance sheet showed we had approximately $3.12 billion
of total debt outstanding. In addition, Unocal Capital Trust, a consolidated
finance subsidiary, has $522 million of convertible preferred securities
outstanding, which represent beneficial interests in a like amount of
subordinated debt issued to the Trust by Unocal. We may incur additional debt in
the future, including in connection with acquisitions, recapitalizations and
refinancings. The level of our debt could have several important effects on our
future operations, including, among others:

o    A significant portion of our cash flow from operations will be applied to
     the payment of principal and interest on the debt and will not be available
     for other purposes;
o    Credit rating agencies have changed and may continue to change their
     ratings of our debt and other obligations as a result of changes in our
     debt level, financial condition, earnings and cash flow, which in turn
     impacts the costs, terms and conditions and availability of financing;
o    Covenants contained in our existing and future debt arrangements will
     require us to meet financial tests that may affect our flexibility in
     planning for and reacting to changes in our business, including possible
     acquisition opportunities;
o    Our ability to obtain additional financing for working capital, capital
     expenditures, acquisitions, general corporate and other purposes may be
     limited or burdened by increased costs or more restrictive covenants;
o    We may be at a competitive disadvantage to similar companies that have less
     debt; and
o    Our vulnerability to adverse economic and industry conditions may increase.

A Change of Control of Unocal Could Result in the Acceleration of Our
Outstanding Bank Borrowings and Trigger Various Change-of-Control Provisions
Included in Employee and Director Plans and Agreements.

Two of our bank credit facilities, under which we can borrow an aggregate of up
to $1,000,000,000, provide for the termination of their loan commitments and
require the prepayment of all outstanding borrowings under the facilities in the
event that (1) any person or group becomes the beneficial owner of more than 30
percent of the then outstanding voting stock of Unocal other than in a
transaction having the approval of Unocal's board of directors, at least a
majority of which are continuing directors, or (2) if continuing directors shall
cease to constitute at least a majority of the board. If this situation were to
occur, we would likely be required to refinance the outstanding indebtedness
under these credit facilities. There can be no assurance that we would be able
to refinance this indebtedness or, if a refinancing were to occur, that the
refinancing would be on terms favorable to us.

Under various employee and director plans and agreements, in the event of a
change in control, restricted stock would become unrestricted, unvested options
and phantom units would vest,

                                       9


performance shares, performance bonus awards and incentive compensation would
be paid out, and directors' units would be paid out if the director has so
elected. We have also entered into employment agreements and other agreements
with certain of our employees containing change-of-control provisions.

We have adopted an enhanced severance program for approximately 2,800
U.S.-payroll employees not represented by collective bargaining agreements and a
limited number of international employees in the event they lose their jobs
through a change of control.

Unocal May Issue Preferred Stock, the Terms of Which Could Adversely Affect the
Voting Power or Value of Its Common Stock.

Unocal's Restated Certificate of Incorporation, which is filed as Exhibit 3.1 to
its amended 2001 Annual Report on Form 10-K/A, authorizes it to issue, upon
approval of its board of directors but without the approval of its stockholders,
one or more classes or series of preferred stock having such preferences, powers
and relative, participating, optional and other rights, including preferences
over its common stock respecting dividends and distributions, as its board of
directors generally may determine. The terms of one or more classes or series of
preferred stock could adversely impact the voting power or value of Unocal's
common stock. For example, Unocal might grant holders of preferred stock the
right to elect some number of its directors in all events or on the happening of
specified events or the right to veto specified transactions. Similarly, the
repurchase or redemption rights or liquidation preferences Unocal might assign
to holders of preferred stock could affect the residual value of the common
stock.

Provisions in Unocal's Corporate Documents and Delaware Law Could Delay or
Prevent a Change of Control of Unocal, Even If That Change Would Be Beneficial
to Its Stockholders.

The existence of some provisions in Unocal's corporate documents and Delaware
law could delay or prevent a change of control of Unocal, even if that change
would be beneficial to its stockholders. Unocal's Restated Certificate of
Incorporation and its Bylaws, which are filed as Exhibit 3.2 to its amended 2001
Annual Report on Form 10-K/A, contain provisions that may make acquiring control
of Unocal difficult, including:

o    Provisions  relating  to the  classification,  nomination  and  removal  of
     directors;
o    A provision prohibiting stockholder action by written consent;

                                       10



o    A  provision  that  allows  only its board of  directors  to call a special
     meeting of its stockholders;
o    Provisions  regulating the ability of its stockholders to bring matters for
     action before annual meetings of its stockholders; and
o    The  authorization  given to its  board of  directors  to issue and set the
     terms of preferred stock.

In addition, Unocal has also adopted a stockholder rights plan, which is filed
as Exhibit 10.1 to its amended 2001 Annual Report on Form 10-K/A, and which
would cause extreme dilution to any person or group that attempts to acquire a
significant interest in Unocal without advance approval of its board of
directors, while a provision of the Delaware General Corporation Law would
impose some restrictions on mergers and other business combinations between
Unocal and any holder of 15 percent or more of its outstanding common stock.

Unocal May Reduce or Cease to Pay Dividends on Its Common Stock.

Unocal's stockholders may receive reduced or no future dividends. The amount of
cash dividends, if any, to be paid in the future will depend upon their
declaration by Unocal's board of directors and upon Unocal's financial
condition, results of operations, cash flow, the level of its capital and
exploration expenditures, its future business prospects and other related
matters that Unocal's board of directors deems relevant.

In addition, under the terms of the outstanding preferred securities of Unocal
Capital Trust and the Unocal subordinated debt securities held by the Trust, in
which the trust preferred securities represent beneficial interests, Unocal has
the right, under certain circumstances to suspend the payment to the Trust of
interest on the debt securities, in which event the Trust has the right to
suspend the payment of distributions on the trust preferred securities. In this
situation, Unocal would be prohibited from paying dividends on the common stock.

                   SPECIAL NOTE ON FORWARD-LOOKING STATEMENTS

Some of the statements contained in or incorporated by reference in this
prospectus discuss our plans and strategies for our business or state other
forward-looking statements, as this term is defined in the Private Securities
Litigation Reform Act of 1995. All statements, other than statements of
historical facts, that address activities, events or developments that we
intend, expect, project, believe or anticipate will or may occur in the future
are forward-looking statements. The words "believes," "anticipates,"
"estimates," "expects," "plans," "intends" and similar expressions are intended
to identify these forward-looking statements, but are not the exclusive means of
identifying them. These statements are based on assumptions and assessments made
by our management in light of its experience and its perception of historical
trends, current conditions, expected future developments and other factors our
management believes to be appropriate. These forward-looking statements are
subject to a number of risks and uncertainties, some of which our management has
not yet identified. Any such forward-looking statements are not guarantees of
future performances and actual results, developments and business decisions may
differ from those envisaged by such forward-looking statements as the result of
various important factors, certain of which but not all of which are discussed
at

                                       11


pages 59-61 of Amendment No. 2 to our 2001 Annual Report on Form 10-K/A and in
other documents incorporated by reference in this Prospectus.

                                 USE OF PROCEEDS

The shares covered by this Prospectus will be sold by the Selling Stockholders
as principals for their own account. The Company will not receive any proceeds
from sales of any such shares.

                              SELLING STOCKHOLDERS

This Prospectus relates to shares of common stock (including the associated
preferred stock purchase rights) that have been acquired by the Selling
Stockholders pursuant to our Executive Stock Purchase Plan which was approved by
stockholders in 2000. Six of the Selling Stockholders are employees of Union Oil
or one of its subsidiaries; the other four are former employees. The following
table sets forth: (a) the name and positions over the past three years with the
company of each Selling Stockholder; (b) the number of shares of common stock
each Selling Stockholder beneficially owned as of October 10, 2002; (c) the
number of shares of common stock acquired by each Selling Stockholder pursuant
to the plan and being registered for resale under this Registration Statement,
some or all of which shares may be sold pursuant to this Prospectus; and (d) the
number of shares of common stock of the total class of common stock outstanding
to be beneficially owned by each Selling Stockholder following this offering,
assuming the sale pursuant to this offering of all shares acquired by such
Selling Stockholder pursuant to the plan and registered under this Registration
Statement. There is no assurance that any of the Selling Stockholders will sell
any or all of the shares offered in this Registration Statement.



----------------------------------------------------------------------------------------------------------------------
            Name                No. of                                                                 No. of
                                Shares     No. of                                                      Shares
                                Before     Resale               Principal Positions with               After
                                Offering   Shares               Company for Last 3 Years               Offering(1)
----------------------------------------------------------------------------------------------------------------------
                                                                                           
---------------------------------------------------------------------------------------------------------------------
Charles R. Williamson           220,375    179,736    Chairman of the Board since October 2001 and     40,639
                                                      Chief Executive Officer since January 2001;
                                                      previously, Executive Vice President,
                                                      International Energy Operations, during 1999
                                                      and 2000, Group Vice President, Asia
                                                      Operations, in 1998 and 1999, Group Vice
                                                      President, International Operations, since 1996
----------------------------------------------------------------------------------------------------------------------

(1) Assuming Selling Stockholders sell all of their resale shares.

                                       12



----------------------------------------------------------------------------------------------------------------------
            Name                No. of                                                                 No. of
                                Shares     No. of                                                      Shares
                                Before     Resale               Principal Positions with               After
                                Offering   Shares               Company for Last 3 Years               Offering(1)
----------------------------------------------------------------------------------------------------------------------
Timothy H. Ling                 233,269    179,736    President and Chief Operating Officer since      53,533
                                                      January 2001; previously, Executive Vice
                                                      President, North American Energy Operations, in
                                                      1999 and 2000, and Chief Financial Officer from
                                                      1997 to 2000; also a director of Pure
                                                      Resources, Inc.
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
Dennis P.R. Codon               122,644    89,868     Senior Vice President, Chief Legal Officer and   32,776
                                                      General Counsel since August 2000; previously,
                                                      Vice President, Chief Legal Officer and General
                                                      Counsel since 1992.
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
Randy L. Howard                 114,828    89,868     Vice President, International Energy             24,960
                                                      Operations--Myanmar, Thailand, Vietnam, since
                                                      June 1999; previously Group Vice President,
                                                      International Operations, Geothermal, since
                                                      1998, and Vice President, Geothermal
                                                      Operations, since 1997
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
Andrew L. Fawthrop               98,503    89,868     Vice President, International Energy              8,635
                                                      Operations--West Africa, Latin America, Caspian
                                                      and Europe, since March 1999; previously New
                                                      Ventures Vice President, West Caspian/Middle
                                                      East, since 1997
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
Brian W.G. Marcotte             108,947    71,894     Vice President, International Energy             37,053
                                                      Operations--Brunei, Indonesia, Philippines,
                                                      since June 1999; previously President, Unocal
                                                      Thailand Ltd. since 1993
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
Roger C. Beach                  271,228    179,736    No longer with the Company; formerly, Chairman   91,492
                                                      of the Board 1995-2000 and Chief Executive
                                                      Officer 1994-2000
----------------------------------------------------------------------------------------------------------------------

(1) Assuming Selling Stockholders sell all of their resale shares.

                                       13

----------------------------------------------------------------------------------------------------------------------
            Name                No. of                                                                 No. of
                                Shares     No. of                                                      Shares
                                Before     Resale               Principal Positions with               After
                                Offering   Shares               Company for Last 3 Years               Offering(1)
----------------------------------------------------------------------------------------------------------------------
John T. Donohue                  1,568      868       No longer with the Company; formerly, President      700
                                                      Spirit Energy 76 1999-2000, and Vice President,
                                                      Agricultural Products 1996-1999
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
R. Boyd Montgomery              48,275     44,868     No longer with the Company; formerly, Vice         3,407
                                                      President, International Energy
                                                      Operations--Bangladesh, China, India, since March
                                                      1999; previously, New Ventures Vice President,
                                                      East Asia/South Asia, since 1997
----------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------------
John C. Ellice-Flint            115,357    89,868     No longer with the Company; formerly, Senior      25,489
                                                      Vice President, Global Exploration and
                                                      Technology, since December 1997
----------------------------------------------------------------------------------------------------------------------


(1) Assuming Selling Stockholders sell all of their resale shares.




                              PLAN OF DISTRIBUTION

It is anticipated that the Selling Stockholders will offer some or all of their
shares for sale at prices prevailing on the New York Stock Exchange on the date
of sale. We will not receive any of the proceeds from the sale of the shares.
The Selling Stockholders will pay all selling and other expenses, if any,
associated with any sale of the shares. We will pay all of the expenses of
registration incurred in connection with this offering.

Each Selling Stockholder and any broker executing selling orders on behalf of
them may be deemed an "underwriter" within the meaning of the Securities Act of
1933, as amended, in which event commissions received by such broker may be
deemed to be underwriting commissions under the Securities Act.

                                  LEGAL MATTERS

Legal matters in connection with the issuance and sale of the securities offered
hereby will be passed upon by Dennis P.R. Codon, Esq., Senior Vice President,
Chief Legal Officer and General Counsel of the Company. As of October 10,
2002, Mr. Codon owned beneficially 122,644 shares of Common Stock. He also held
options to purchase 212,218 shares of common stock at prices ranging from
$32.8125 to $38.8125, with expiration dates ranging from 2006 to 2011. In
addition, Mr. Codon held 19,500 performance share units, which could be paid out
in up to 39,000 shares of common stock four years after their award dates,
depending upon our total return to stockholders.

                                       14



                                     EXPERTS

The financial statements incorporated in this Prospectus by reference to our
amended 2001 Annual Report on Form 10-K/A have been so incorporated in reliance
on the report of PricewaterhouseCoopers LLP, independent accountants, given on
the authority of said firm as experts in auditing and accounting.

                       WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and special reports, proxy statements and other
information with the Securities and Exchange Commission (the "SEC"). Our SEC
filings are available to the public over the Internet at the SEC's web site at
http://www.sec.gov. You may also read and copy any materials we file with the
SEC at the SEC's Public Reference Room at 450 Fifth Street, N.W., Washington,
D.C. 20549. Please call the SEC at 1-800-SEC-0330 for further information on the
SEC's public reference facilities.

We have filed a registration statement with the SEC on Form S-3 pursuant to the
Securities Act of 1933 for the shares of common stock offered by this
Prospectus. In accordance with the rules and regulations of the SEC, this
Prospectus does not contain all of the information set forth in the registration
statement. For further information regarding the shares of common stock offered
by this Prospectus, you may examine our registration statement and the documents
incorporated therein by reference without charge at the SEC's public reference
facilities identified above.

Our reports, proxy statements and other information can also be inspected and
copied at the offices of the New York Stock Exchange at 20 Broad Street, 17th
Floor, New York, New York 10005. Our common stock is listed on the New York
Stock Exchange.

The SEC allows us to incorporate by reference the information we file with the
SEC. This means that we can disclose important information to you by referring
you to the documents we file with the SEC. The information incorporated by
reference is an important part of this prospectus, and information that we file
later with the SEC will automatically update and supersede this information. We
incorporate by reference the documents listed below and any future filings made
with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Securities and
Exchange Act of 1934, including any filings made after the date of this
registration statement but prior to its effectiveness:

a.   Our Annual Report on Form 10-K,  as amended by  Amendments  Nos. 1 and 2 on
     Form 10-K/A, for the fiscal year ended December 31, 2001;

b.   Our Quarterly  Report on Form 10-Q for the quarterly period ended March 31,
     and our Quarterly  Report on Form 10-Q, as amended by Amendments Nos. 1 and
     2 on Form 10-Q/A, for the quarterly period ended June 30, 2002;

                                       15



c.   Our Current  Reports on Form 8-K dated (date of  earliest  event  reported)
     January 22 and 24, March 27,  April 8 and 25, and June 10 and 20,  August 2
     and 20, September  4, 13, 18, 25, and 27, as amended by Amendment No. 1 on
     Form 8-K/A, and October 1 and 8, 2002;

d.   All of our other  reports  filed  pursuant to Section 13(a) or 15(d) of the
     Securities  Exchange Act of 1934, as amended (the  "Exchange  Act"),  since
     December 31, 2001; and

e.   The description of our Common Stock,  $1.00 par value per share,  excluding
     that of the associated Preferred Stock Purchase Rights, set forth under the
     caption "Description of the Common Stock," included in the prospectus dated
     September 25, 1998,  of Union Oil Company of  California  and us (File Nos.
     333-58415  and  333-58415-01),  together  with the  description  of our now
     associated  Preferred  Share Purchase Rights included in our Current Report
     on Form 8-K dated  January 5, 2000,  as they have been amended as set forth
     in our Current  Reports on Form 8-K dated (date of earliest event reported)
     March  27  and  August  2,  2002.  The  descriptions  of  the  6.25%  Trust
     Convertible  Preferred  Securities  of Unocal  Capital  Trust,  (the "Trust
     Convertible  Preferred  Securities"),  the guarantee thereof by us, and our
     6.25% Convertible Junior  Subordinated  Debentures (as the rights and terms
     of which may  materially  limit or  qualify  the  rights  evidenced  by, or
     amounts  payable  with  respect  to, our common  stock) set forth under the
     captions  "Description  of the  Trust  Convertible  Preferred  Securities,"
     "Description   of  the   Guarantee,"   "Description   of  the   Convertible
     Debentures,"  and "Effect of Obligations  under the Convertible  Debentures
     and the Guarantee" in the prospectus dated August 7, 1996,  included in the
     Registration Statement on Form S-4 of Unocal and Unocal Capital Trust (File
     Nos. 333-09137 and 333-09137-01), as amended by Pre-Effective Amendment No.
     1.

All documents filed by us pursuant to Sections 13(a), 13(c), 14 and 15(d) of the
Exchange Act prior to the filing of a post-effective amendment which indicates
that all securities offered have been sold or which deregisters all securities
then remaining unsold, shall be deemed to be incorporated by reference in this
Prospectus and to be a part hereof from the date of filing of such documents.

You may obtain copies of certain documents referred to above at our web site at
http://www.unocal.com. You also may obtain a copy of any such document at no
charge by writing or telephoning us at the following:

                         Stockholder Services Department
                               Unocal Corporation
                        2141 Rosecrans Avenue, Suite 4000
                          El Segundo, California 90245
                                 (800) 252-2233

                                       16