PAGE 1 000 B000000 08/31/2008 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 013 A000001 DELOITTE & TOUCHE LLP PAGE 2 013 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 CAPITAL MARKETS, LLC 014 B000002 8-67827 014 A000003 BLACKROCK INVESTMENTS, INC. 014 B000003 8-048436 014 A000004 NORTHERN FUNDS DISTRIBUTORS, LLC 014 B000004 8-051242 014 A000005 PNC CAPITAL MARKETS, INC. 014 B000005 8-32493 014 A000006 PFPC DISTRIBUTORS, INC. 014 B000006 8-045467 014 A000007 MGI FUNDS DISTRIBUTOR, INC. 014 B000007 8-046960 014 A000008 BB & T AM DISTRIBUTORS, INC. 014 B000008 8-52396 014 A000009 BLACKROCK DISTRIBUTORS, INC. 014 B000009 8-048775 014 A000010 PNC INVESTMENTS LLC 014 B000010 8-066195 014 A000011 HARRIS WILLIAMS LLC 014 B000011 8-53380 014 A000012 DSP MERRILL LYNCH LIMITED 014 B000012 8-00000 014 A000013 FAM DISTRIBUTORS, INC. 014 B000013 8-14663 014 A000014 FIRST REPUBLIC SECURITIES COMPANY, LLC 014 B000014 8-52973 014 A000015 GPC SECURITIES, INC. 014 B000015 8-30108 014 A000016 BERNDALE SECURITIES LIMITED 014 B000016 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 THE BANK OF NEW YORK MELLON 015 B000002 S 015 C010002 NEW YORK 015 C020002 NY 015 C030002 10286 015 E010002 X 015 A000003 J.P. MORGAN CHASE BANK 015 B000003 S 015 C010003 NEW YORK 015 C020003 NY PAGE 3 015 C030003 10017 015 E010003 X 018 000000 Y 019 A000000 Y 019 B000000 301 019 C000000 BLKRKADVSR 020 A000001 CITIGROUP GLOBAL MARKETS, INC. 020 B000001 11-2418191 020 C000001 37 020 A000002 UBS SECURITIES LLC 020 B000002 13-3873456 020 C000002 32 020 A000003 LEHMAN BROTHERS INC. 020 B000003 13-2518466 020 C000003 10 020 A000004 J.P. MORGAN SECURITIES INC. 020 B000004 13-3224016 020 C000004 4 020 A000005 BANC OF AMERICA SECURITIES LLC 020 B000005 56-2058405 020 C000005 2 020 A000006 CREDIT SUISSE SECURITIES (USA) L.L.C. 020 B000006 13-5659485 020 C000006 2 020 A000007 DEUTSCHE BANK SECURITIES INC. 020 B000007 13-2730828 020 C000007 1 020 A000008 GOLDMAN, SACHS & CO. 020 B000008 13-5108880 020 C000008 1 020 A000009 MORGAN STANLEY & CO. INCORPORATED 020 B000009 13-2655998 020 C000009 1 020 A000010 MERRILL LYNCH, PIERCE, FENNER & SMITH INCORP. 020 B000010 13-5674085 020 C000010 0 021 000000 89 022 A000001 LEHMAN BROTHERS INC. 022 B000001 13-2518466 022 C000001 1677305 022 D000001 2822227 022 A000002 J.P. MORGAN SECURITIES INC. 022 B000002 13-3224016 022 C000002 403378 022 D000002 526891 022 A000003 CREDIT SUISSE SECURITIES (USA) L.L.C. 022 B000003 13-5659485 022 C000003 371101 022 D000003 319734 022 A000004 DEUTSCHE BANK SECURITIES INC. 022 B000004 13-2730828 PAGE 4 022 C000004 338069 022 D000004 333076 022 A000005 BARCLAYS CAPITAL INC. 022 C000005 388707 022 D000005 141341 022 A000006 CITIGROUP GLOBAL MARKETS, INC. 022 B000006 11-2418191 022 C000006 58078 022 D000006 74483 022 A000007 BEAR, STEARNS & CO. INC. 022 B000007 13-3299429 022 C000007 37581 022 D000007 31322 022 A000008 GOLDMAN, SACHS & CO. 022 B000008 13-5108880 022 C000008 40172 022 D000008 27672 022 A000009 BANC OF AMERICA SECURITIES LLC 022 B000009 56-2058405 022 C000009 41532 022 D000009 15423 022 A000010 MORGAN STANLEY & CO. INCORPORATED 022 B000010 13-2655998 022 C000010 21635 022 D000010 16480 023 C000000 3418241 023 D000000 4335978 024 000000 Y 025 A000001 CITIGROUP, INC. 025 C000001 D 025 D000001 12170 025 A000002 MORGAN STANLEY 025 C000002 D 025 D000002 4417 025 A000003 UBS AG SERIES DPNT 025 C000003 D 025 D000003 2510 025 A000004 JPMORGAN CHASE CAPITAL XXV 025 C000004 D 025 D000004 2373 025 A000005 JPMORGAN CHASE & CO. 025 C000005 D 025 D000005 1870 025 A000006 BARCLAYS BANK, PLC 025 C000006 E 025 D000006 1745 025 A000007 LEHMAN BROTHERS HOLDINGS, INC. 025 C000007 D 025 D000007 1600 025 A000008 THE GOLDMAN SACHS GROUP, INC. 025 C000008 D PAGE 5 025 D000008 858 025 A000009 CITIGROUP INC. 025 C000009 E 025 D000009 507 025 D000010 0 025 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 PAGE 6 053 A000000 N 054 A000000 Y 054 B000000 Y 054 C000000 N 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 0.8 062 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 -0.5 062 L000000 0.0 062 M000000 10.6 062 N000000 20.8 062 O000000 0.0 062 P000000 58.4 062 Q000000 36.3 062 R000000 0.1 063 A000000 0 063 B000000 20.9 064 A000000 N 064 B000000 Y 065 000000 N 066 A000000 N 067 000000 N 068 A000000 N 068 B000000 N PAGE 7 069 000000 N 070 A010000 Y 070 A020000 Y 070 B010000 N 070 B020000 N 070 C010000 Y 070 C020000 N 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 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 N 071 A000000 2814169 071 B000000 2918270 071 C000000 463987 071 D000000 607 072 A000000 10 072 B000000 20160 072 C000000 256 072 D000000 0 072 E000000 86 072 F000000 2265 072 G000000 75 072 H000000 0 072 I000000 7 072 J000000 52 PAGE 8 072 K000000 0 072 L000000 76 072 M000000 28 072 N000000 10 072 O000000 0 072 P000000 4180 072 Q000000 0 072 R000000 71 072 S000000 5 072 T000000 0 072 U000000 0 072 V000000 0 072 W000000 95 072 X000000 6864 072 Y000000 4 072 Z000000 13642 072AA000000 46256 072BB000000 54801 072CC010000 0 072CC020000 10369 072DD010000 16387 072DD020000 0 072EE000000 500 073 A010000 0.6100 073 A020000 0.0000 073 B000000 0.0200 073 C000000 0.0000 074 A000000 3626 074 B000000 0 074 C000000 2997 074 D000000 457724 074 E000000 507 074 F000000 0 074 G000000 0 074 H000000 3367 074 I000000 1 074 J000000 20922 074 K000000 0 074 L000000 7931 074 M000000 15964 074 N000000 513039 074 O000000 20346 074 P000000 220 074 Q000000 0 074 R010000 107690 074 R020000 0 074 R030000 5427 074 R040000 33179 074 S000000 0 074 T000000 346177 074 U010000 27019 PAGE 9 074 U020000 0 074 V010000 12.81 074 V020000 0.00 074 W000000 0.0000 074 X000000 17018 074 Y000000 197508 075 A000000 0 075 B000000 357747 076 000000 11.51 077 A000000 Y 077 B000000 Y 077 O000000 Y 078 000000 N 080 A000000 VIGILANT INSURANCE COMPANY 080 C000000 750 081 A000000 Y 081 B000000 113 082 A000000 N 082 B000000 0 083 A000000 N 083 B000000 0 084 A000000 N 084 B000000 0 085 A000000 Y 085 B000000 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 N SIGNATURE DONALD C. BURKE TITLE PRESIDENT