    <SEC-DOCUMENT>0001193125-21-264310-index.html : 20210902
    <SEC-HEADER>0001193125-21-264310.hdr.sgml : 20210902
    <ACCEPTANCE-DATETIME>20210902140409
    ACCESSION NUMBER:		0001193125-21-264310
    CONFORMED SUBMISSION TYPE:	N-CSRS
    PUBLIC DOCUMENT COUNT:		11
    CONFORMED PERIOD OF REPORT:	20210630
    FILED AS OF DATE:		20210902
    DATE AS OF CHANGE:		20210902
    EFFECTIVENESS DATE:		20210902

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			BLACKROCK CORE BOND TRUST
    		CENTRAL INDEX KEY:			0001160864
    		IRS NUMBER:				522346891
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1031

    	FILING VALUES:
    		FORM TYPE:		N-CSRS
    		SEC ACT:		1940 Act
    		SEC FILE NUMBER:	811-10543
    		FILM NUMBER:		211232625

    	BUSINESS ADDRESS:
    		STREET 1:		100 BELLEVUE PARKWAY
    		STREET 2:		MUTUAL FUND DEPARTMENT
    		CITY:			WILMINGTON
    		STATE:			DE
    		ZIP:			19809
    		BUSINESS PHONE:		888-825-2257

    	MAIL ADDRESS:
    		STREET 1:		100 BELLEVUE PARKWAY
    		STREET 2:		MUTUAL FUND DEPARTMENT
    		CITY:			WILMINGTON
    		STATE:			DE
    		ZIP:			19809
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>N-CSRS
    <SEQUENCE>1
    <FILENAME>d210240dncsrs.htm
    <DESCRIPTION>BLACKROCK CORE BOND TRUST
    <TEXT>
    Document 1 - file: d210240dncsrs.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.CERT
    <SEQUENCE>2
    <FILENAME>d210240dex99cert.htm
    <DESCRIPTION>CERTIFICATION PURSUANT TO SECTION 302
    <TEXT>
    Document 2 - file: d210240dex99cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.906CERT
    <SEQUENCE>3
    <FILENAME>d210240dex99906cert.htm
    <DESCRIPTION>CERTIFICATION PURSUANT TO SECTION 906
    <TEXT>
    Document 3 - file: d210240dex99906cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>g210240dsp004a.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 4 - file: g210240dsp004a.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>g210240dsp004b.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 5 - file: g210240dsp004b.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>g210240g42l24.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: g210240g42l24.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>g210240g46r12.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: g210240g46r12.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>g210240g72w27.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: g210240g72w27.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>g210240leaf.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: g210240leaf.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>g210240s1.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: g210240s1.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>g210240s3.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: g210240s3.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>