PAGE 1
000 A000000 04/30/2005
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 8888252257
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, INC.
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 EQUISERVE TRUST COMPANY, NA
012 B000001 85-11340
012 C010001 CANTON
012 C020001 MA
012 C030001 02021
013 A000001 DELOITTE & TOUCHE LLP
013 B010001 BOSTON
PAGE 2
013 B020001 MA
013 B030001 02116
014 A000001 BLACKROCK INVESTMENTS, INC.
014 B000001 8-048436
014 A000002 NORTHERN FUND DISTRIBUTORS, LLC
014 B000002 8-051242
014 A000003 PNC CAPITAL MARKETS, INC.
014 B000003 8-032493
014 A000004 J.J.B. HILLIARD W.L. LYONS, INC.
014 B000004 8-033133
014 A000005 PFPC DISTRIBUTORS, INC.
014 B000005 8-045467
014 A000006 OFFIT FUNDS DISTRIBUTOR, INC.
014 B000006 8-046960
014 A000007 ABN AMRO DISTRIBUTION SERVICES (USA), INC.
014 B000007 8-052396
014 A000008 BLACKROCK DISTRIBUTORS, INC.
014 B000008 8-048775
014 A000009 PERSIMMON SECURITIES
014 B000009 8-053071
015 A000001 STATESTREET BANK AND TRUST COMPANY
015 B000001 C
015 C010001 BOSTON
015 C020001 MA
015 C030001 02171
015 E010001 X
015 A000002 PRUDENTIAL SECURITIES, INC.
015 B000002 C
015 C010002 SPRING LAKE
015 C020002 NJ
015 C030002 07762
015 C040002 1443
015 E020002 X
018 000000 Y
019 A000000 Y
019 B000000 54
019 C000000 BLACKROCKF
020 A000001 CITIGROUP GLOBAL MARKETS INC.
020 B000001 11-2418191
020 C000001 38
020 C000002 0
020 C000003 0
020 C000004 0
020 C000005 0
020 C000006 0
020 C000007 0
020 C000008 0
020 C000009 0
020 C000010 0
021 000000 38
022 A000001 LEHMAN BROTHERS INC.
PAGE 3
022 B000001 13-2518466
022 C000001 1601219
022 D000001 1410403
022 A000002 CREDIT SUISSE FIRST BOSTON
022 B000002 13-5659485
022 C000002 697627
022 D000002 538827
022 A000003 BARCLAYS CAPITAL
022 B000003 06-1031656
022 C000003 482667
022 D000003 297580
022 A000004 MORGAN STANLEY CO
022 B000004 13-2655998
022 C000004 103193
022 D000004 199745
022 A000005 CITIGROUP GLOBAL MARKETS
022 B000005 11-2418191
022 C000005 146363
022 D000005 134183
022 A000006 GOLDMAN SACHS
022 B000006 13-5108880
022 C000006 107052
022 D000006 108353
022 A000007 MIZUHO SECURITIES
022 B000007 36-2880742
022 C000007 175886
022 D000007 0
022 A000008 MERRILL LYNCH
022 B000008 13-5674085
022 C000008 113906
022 D000008 26784
022 A000009 HSBC
022 B000009 13-2650272
022 C000009 70204
022 D000009 0
022 A000010 UBS FINANCIAL SERVICES INC.
022 B000010 13-2638166
022 C000010 17998
022 D000010 46640
023 C000000 3750265
023 D000000 2906572
024 000000 Y
025 A000001 CITIGROUP GLOBAL MARKETS
025 B000001 11-2418191
025 C000001 D
025 D000001 12410
025 A000002 GOLDMAN SACHS
025 B000002 13-5108880
025 C000002 D
025 D000002 3038
025 A000003 HSBC
PAGE 4
025 B000003 13-2650272
025 C000003 D
025 D000003 3760
025 A000004 MORGAN STANLEY
025 B000004 13-2655998
025 C000004 D
025 D000004 3246
025 A000005 DELETE
025 D000005 0
025 A000006 DELETE
025 D000006 0
025 A000007 DELETE
025 D000007 0
025 A000008 DELETE
025 D000008 0
025 A000009 CITIGROUP GLOBAL MARKETS INC.
025 B000009 11-2418191
025 C000009 D
025 D000009 5940
025 A000010 WACHOVIA BANK N.A.
025 B000010 34-1542819
025 C000010 D
025 D000010 1261
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
028 A010000 0
028 A020000 0
028 A030000 0
028 A040000 0
028 B010000 0
028 B020000 0
028 B030000 0
028 B040000 0
028 C010000 0
028 C020000 0
028 C030000 0
028 C040000 0
PAGE 5
028 D010000 0
028 D020000 0
028 D030000 0
028 D040000 0
028 E010000 0
028 E020000 0
028 E030000 0
028 E040000 0
028 F010000 0
028 F020000 0
028 F030000 0
028 F040000 0
028 G010000 0
028 G020000 0
028 G030000 0
028 G040000 0
028 H000000 0
030 A000000 0
030 B000000 0.00
030 C000000 0.00
031 A000000 0
031 B000000 0
032 000000 0
033 000000 0
035 000000 0
036 B000000 0
038 000000 0
042 A000000 0
042 B000000 0
042 C000000 0
042 D000000 0
042 E000000 0
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 0
044 000000 0
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
PAGE 6
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
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 Y
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 N
054 M000000 Y
054 N000000 N
054 O000000 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 0.0
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
PAGE 7
062 K000000 -0.4
062 L000000 0.0
062 M000000 47.4
062 N000000 20.7
062 O000000 0.3
062 P000000 60.0
062 Q000000 14.0
062 R000000 0.0
063 A000000 0
063 B000000 8.8
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
070 C010000 Y
070 C020000 Y
070 D010000 N
070 D020000 N
070 E010000 Y
070 E020000 Y
070 F010000 N
070 F020000 N
070 G010000 Y
070 G020000 Y
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 Y
070 K010000 Y
070 K020000 N
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
PAGE 8
070 R010000 Y
070 R020000 N
071 A000000 872829
071 B000000 824346
071 C000000 552374
071 D000000 149
072 A000000 6
072 B000000 11596
072 C000000 2
072 D000000 0
072 E000000 0
072 F000000 1333
072 G000000 0
072 H000000 0
072 I000000 7
072 J000000 91
072 K000000 0
072 L000000 65
072 M000000 29
072 N000000 7
072 O000000 0
072 P000000 851
072 Q000000 0
072 R000000 21
072 S000000 30
072 T000000 0
072 U000000 0
072 V000000 0
072 W000000 46
072 X000000 2480
072 Y000000 0
072 Z000000 9118
072AA000000 12664
072BB000000 0
072CC010000 0
072CC020000 12327
072DD010000 23226
072DD020000 14185
072EE000000 5955
073 A010000 0.5250
073 A020000 0.0000
073 B000000 0.2204
073 C000000 0.0000
074 A000000 836
074 B000000 0
074 C000000 399
074 D000000 570348
074 E000000 0
074 F000000 0
074 G000000 0
074 H000000 0
PAGE 9
074 I000000 4851
074 J000000 113274
074 K000000 0
074 L000000 6701
074 M000000 7808
074 N000000 704217
074 O000000 218923
074 P000000 213
074 Q000000 0
074 R010000 70622
074 R020000 4820
074 R030000 1764
074 R040000 7396
074 S000000 0
074 T000000 400479
074 U010000 27019
074 U020000 0
074 V010000 14.82
074 V020000 0.00
074 W000000 0.0000
074 X000000 90
074 Y000000 72295
075 A000000 0
075 B000000 405097
076 000000 13.78
077 A000000 N
078 000000 N
080 C000000 0
081 B000000 0
082 B000000 0
083 B000000 0
084 B000000 0
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 N
PAGE 10
SIGNATURE HENRY GABBAY
TITLE TREASURER