PAGE  1
000 A000000 04/30/2008
000 C000000 0001160864
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 A
001 A000000 BLACKROCK CORE BOND TRUST
001 B000000 811-10543
001 C000000 8004417762
002 A000000 100 BELLEVUE PARKWAY
002 B000000 WILMINGTON
002 C000000 DE
002 D010000 19809
003  000000 N
004  000000 N
005  000000 N
006  000000 N
007 A000000 N
007 B000000  0
007 C010100  1
007 C010200  2
007 C010300  3
007 C010400  4
007 C010500  5
007 C010600  6
007 C010700  7
007 C010800  8
007 C010900  9
007 C011000 10
008 A000001 BLACKROCK ADVISORS, LLC
008 B000001 A
008 C000001 801-47710
008 D010001 WILMINGTON
008 D020001 DE
008 D030001 19809
008 A000002 BLACKROCK FINANCIAL MANAGEMENT, INC.
008 B000002 S
008 C000002 801-48433
008 D010002 NEW YORK
008 D020002 NY
008 D030002 10022
012 A000001 COMPUTERSHARE TRUST COMPANIES, N.A.
012 B000001 85-11340
012 C010001 PROVIDENCE
012 C020001 RI
012 C030001 02940
012 C040001 3010
012 A000002 DELETE
      PAGE  2
013 A000001 DELOITTE & TOUCHE LLP
013 B010001 PRINCETON
013 B020001 NJ
013 B030001 08540
014 A000001 MLPF&S AND OTHER ML BROKER/DEALER AFFILIATES
014 B000001 8-7221
014 A000002 BLACKROCK INVESTMENTS, INC.
014 B000002 8-048436
014 A000003 NORTHERN FUNDS DISTRIBUTORS, LLC
014 B000003 8-051242
014 A000004 PNC CAPITAL MARKETS, INC.
014 B000004 8-32493
014 A000005 PFPC DISTRIBUTORS, INC.
014 B000005 8-045467
014 A000006 MGI FUNDS DISTRIBUTOR, INC.
014 B000006 8-046960
014 A000007 BB & T AM DISTRIBUTORS, INC.
014 B000007 8-52396
014 A000008 BLACKROCK DISTRIBUTORS, INC.
014 B000008 8-048775
014 A000009 PNC INVESTMENTS LLC
014 B000009 8-066195
014 A000010 HARRIS WILLIAMS LLC
014 B000010 8-53380
014 A000011 DSP MERRILL LYNCH LIMITED
014 B000011 8-00000
014 A000012 FAM DISTRIBUTORS, INC.
014 B000012 8-14663
014 A000013 FIRST REPUBLIC SECURITIES COMPANY, LLC
014 B000013 8-52973
014 A000014 GPC SECURITIES, INC.
014 B000014 8-30108
014 A000015 BERNDALE SECURITIES LIMITED
014 B000015 8-00000
015 A000001 STATE STREET BANK AND TRUST COMPANY
015 B000001 C
015 C010001 BOSTON
015 C020001 MA
015 C030001 02101
015 E010001 X
015 A000002 WACHOVIA SECURITIES
015 B000002 S
015 C010002 SPRING LAKE
015 C020002 NJ
015 C030002 07762
015 C040002 1443
015 E010002 X
018  000000 Y
019 A000000 Y
019 B000000  301
019 C000000 BLKRKADVSR
      PAGE  3
020 A000001 CITIGROUP GLOBAL MARKETS, INC.
020 B000001 11-2418191
020 C000001     22
020 A000002 UBS SECURITIES LLC
020 B000002 13-3873456
020 C000002     22
020 A000003 LEHMAN BROTHERS INC.
020 B000003 13-2518466
020 C000003      5
020 A000004 J.P. MORGAN SECURITIES INC.
020 B000004 13-3224016
020 C000004      3
020 A000005 GOLDMAN, SACHS & CO.
020 B000005 13-5108880
020 C000005      1
020 A000006 DEUTSCHE BANK SECURITIES INC.
020 B000006 13-2730828
020 C000006      1
020 A000007 BANC OF AMERICA SECURITIES LLC
020 B000007 56-2058405
020 C000007      0
020 A000008 MORGAN STANLEY & CO. INCORPORATED
020 B000008 13-2655998
020 C000008      0
020 A000009 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
020 B000009 13-5674085
020 C000009      0
020 A000010 CREDIT SUISSE SECURITIES (USA) L.L.C.
020 B000010 13-5659485
020 C000010      0
021  000000       54
022 A000001 LEHMAN BROTHERS INC.
022 B000001 13-2518466
022 C000001   1482655
022 D000001   2228038
022 A000002 J.P. MORGAN SECURITIES INC.
022 B000002 13-3224016
022 C000002    384864
022 D000002    477484
022 A000003 DEUTSCHE BANK SECURITIES INC.
022 B000003 13-2730828
022 C000003    289000
022 D000003    273317
022 A000004 CREDIT SUISSE SECURITIES (USA) L.L.C.
022 B000004 13-5659485
022 C000004    232514
022 D000004    206324
022 A000005 BARCLAYS CAPITAL INC.
022 C000005    287621
022 D000005     80466
022 A000006 CITIGROUP GLOBAL MARKETS, INC.
      PAGE  4
022 B000006 11-2418191
022 C000006     39138
022 D000006     68096
022 A000007 BEAR, STEARNS & CO. INC.
022 B000007 13-3299429
022 C000007     37376
022 D000007     31322
022 A000008 BANC OF AMERICA SECURITIES LLC
022 B000008 56-2058405
022 C000008     30404
022 D000008      9261
022 A000009 GOLDMAN, SACHS & CO.
022 B000009 13-5108880
022 C000009     17139
022 D000009     20547
022 A000010 MORGAN STANLEY & CO. INCORPORATED
022 B000010 13-2655998
022 C000010     21635
022 D000010     12511
023 C000000    2855213
023 D000000    3416029
024  000000 Y
025 A000001 CITIGROUP, INC.
025 C000001 D
025 D000001   13334
025 A000002 MORGAN STANLEY
025 C000002 D
025 D000002    6613
025 A000003 THE GOLDMAN SACHS GROUP, INC.
025 C000003 D
025 D000003    5895
025 A000004 JPMORGAN CHASE CAPITAL XXV
025 C000004 D
025 D000004    3743
025 A000005 JPMORGAN CHASE & CO.
025 C000005 D
025 D000005    1961
025 A000006 LEHMAN BROTHERS HOLDINGS, INC.
025 C000006 D
025 D000006    1734
025 A000007 THE BEAR STEARNS COS., INC.
025 C000007 D
025 D000007    1332
025 A000008 CREDIT SUISSE GUERNSEY LTD.
025 C000008 D
025 D000008    1312
025 A000009 CITIGROUP INC.
025 C000009 E
025 D000009     646
025 A000010 JPMORGAN CHASE & CO.
025 C000010 D
      PAGE  5
025 D000010     130
025 D000011       0
025 D000012       0
025 D000013       0
025 D000014       0
025 D000015       0
025 D000016       0
026 A000000 N
026 B000000 N
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027  000000 N
045  000000 Y
046  000000 N
047  000000 Y
048  000000  0.550
048 A010000        0
048 A020000 0.000
048 B010000        0
048 B020000 0.000
048 C010000        0
048 C020000 0.000
048 D010000        0
048 D020000 0.000
048 E010000        0
048 E020000 0.000
048 F010000        0
048 F020000 0.000
048 G010000        0
048 G020000 0.000
048 H010000        0
048 H020000 0.000
048 I010000        0
048 I020000 0.000
048 J010000        0
048 J020000 0.000
048 K010000        0
048 K020000 0.000
049  000000 N
050  000000 N
051  000000 N
052  000000 N
053 A000000 N
054 A000000 Y
054 B000000 Y
054 C000000 N
      PAGE  6
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 N
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 N
054 M000000 Y
054 N000000 N
055 A000000 Y
055 B000000 N
056  000000 Y
057  000000 N
058 A000000 N
059  000000 Y
060 A000000 Y
060 B000000 Y
061  000000        0
062 A000000 Y
062 B000000   0.0
062 C000000   0.1
062 D000000   0.0
062 E000000   0.0
062 F000000   0.0
062 G000000   0.0
062 H000000   0.0
062 I000000   0.0
062 J000000   0.0
062 K000000   1.2
062 L000000   0.0
062 M000000  13.7
062 N000000  29.6
062 O000000   0.0
062 P000000  68.1
062 Q000000  30.3
062 R000000   1.6
063 A000000   0
063 B000000 19.5
064 A000000 N
064 B000000 N
066 A000000 N
067  000000 N
068 A000000 N
068 B000000 N
069  000000 N
070 A010000 Y
070 A020000 Y
070 B010000 N
070 B020000 N
      PAGE  7
070 C010000 Y
070 C020000 Y
070 D010000 N
070 D020000 Y
070 E010000 Y
070 E020000 Y
070 F010000 N
070 F020000 N
070 G010000 Y
070 G020000 N
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 N
070 K010000 Y
070 K020000 Y
070 L010000 Y
070 L020000 Y
070 M010000 Y
070 M020000 Y
070 N010000 Y
070 N020000 N
070 O010000 Y
070 O020000 N
070 P010000 Y
070 P020000 N
070 Q010000 N
070 Q020000 N
070 R010000 Y
070 R020000 Y
071 A000000   2424692
071 B000000   2485513
071 C000000    574553
071 D000000  422
072 A000000  6
072 B000000    16378
072 C000000      168
072 D000000        0
072 E000000        0
072 F000000     1373
072 G000000       46
072 H000000        0
072 I000000        5
072 J000000       36
072 K000000        0
072 L000000       29
072 M000000       23
072 N000000        5
072 O000000        0
      PAGE  8
072 P000000     6140
072 Q000000        0
072 R000000       42
072 S000000       12
072 T000000        0
072 U000000        0
072 V000000        0
072 W000000       57
072 X000000     7768
072 Y000000        3
072 Z000000     8781
072AA000000    32970
072BB000000    38890
072CC010000     1150
072CC020000        0
072DD010000    10186
072DD020000        0
072EE000000        0
073 A010000   0.3720
073 A020000   0.0000
073 B000000   0.0000
073 C000000   0.0000
074 A000000      146
074 B000000        0
074 C000000      600
074 D000000   513024
074 E000000     5816
074 F000000        0
074 G000000        0
074 H000000        0
074 I000000     4355
074 J000000    84529
074 K000000        0
074 L000000     8117
074 M000000    21239
074 N000000   637826
074 O000000    23270
074 P000000      234
074 Q000000        0
074 R010000   152895
074 R020000        0
074 R030000     2080
074 R040000    97187
074 S000000        0
074 T000000   362160
074 U010000    27019
074 U020000        0
074 V010000    13.40
074 V020000     0.00
074 W000000   0.0000
074 X000000    16664
      PAGE  9
074 Y000000   320336
075 A000000        0
075 B000000   361058
076  000000    12.30
077 A000000 Y
077 O000000 Y
078  000000 N
086 A010000      0
086 A020000      0
086 B010000      0
086 B020000      0
086 C010000      0
086 C020000      0
086 D010000      0
086 D020000      0
086 E010000      0
086 E020000      0
086 F010000      0
086 F020000      0
087 A010000 COMMON STOCK
087 A020000 09249E101
087 A030000 BHK
088 A000000 N
088 B000000 N
088 C000000 N
088 D000000 Y
SIGNATURE   DONALD C. BURKE
TITLE       PRESIDENT