<SEC-DOCUMENT>0001193125-19-262472-index.html : 20191004
<SEC-HEADER>0001193125-19-262472.hdr.sgml : 20191004
<ACCEPTANCE-DATETIME>20191004120314
ACCESSION NUMBER:		0001193125-19-262472
CONFORMED SUBMISSION TYPE:	N-CSR
PUBLIC DOCUMENT COUNT:		20
CONFORMED PERIOD OF REPORT:	20190731
FILED AS OF DATE:		20191004
DATE AS OF CHANGE:		20191004
EFFECTIVENESS DATE:		20191004

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BLACKROCK MUNIYIELD INVESTMENT QUALITY FUND
		CENTRAL INDEX KEY:			0000891188
		IRS NUMBER:				223196058
		FISCAL YEAR END:			0630

	FILING VALUES:
		FORM TYPE:		N-CSR
		SEC ACT:		1940 Act
		SEC FILE NUMBER:	811-07156
		FILM NUMBER:		191137993

	BUSINESS ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19809
		BUSINESS PHONE:		800-441-7762

	MAIL ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19809

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BLACKROCK MUNIYIELD INSURED INVESTMENT FUND
		DATE OF NAME CHANGE:	20080926

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BLACKROCK MUNIYIELD FLORIDA INSURED FUND
		DATE OF NAME CHANGE:	20070611

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MUNIYIELD FLORIDA INSURED FUND /NJ/
		DATE OF NAME CHANGE:	19921217
</SEC-HEADER>
<DOCUMENT>
<TYPE>N-CSR
<SEQUENCE>1
<FILENAME>d725029dncsr.htm
<DESCRIPTION>BLACKROCK MUNIYIELD INVESTMENT QUALITY FUND
<TEXT>
Document 1 - file: d725029dncsr.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.CERT
<SEQUENCE>2
<FILENAME>d725029dex99cert.htm
<DESCRIPTION>CERTIFICATION PURSUANT TO SECTION 302
<TEXT>
Document 2 - file: d725029dex99cert.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.906CERT
<SEQUENCE>3
<FILENAME>d725029dex99906cert.htm
<DESCRIPTION>CERTIFICATION PURSUANT TO SECTION 906
<TEXT>
Document 3 - file: d725029dex99906cert.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.PROXY.POL
<SEQUENCE>4
<FILENAME>d725029dex99proxypol.htm
<DESCRIPTION>CLOSED END PROXY VOTING POLICY
<TEXT>
Document 4 - file: d725029dex99proxypol.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.CORP.GOV
<SEQUENCE>5
<FILENAME>d725029dex99corpgov.htm
<DESCRIPTION>GLOBAL CORPORATE GOVERNANCE GUIDELINES & ENGAGEMENT PRINCIPLES
<TEXT>
Document 5 - file: d725029dex99corpgov.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>6
<FILENAME>g725027g10p11.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 6 - file: g725027g10p11.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>7
<FILENAME>g725027g12p13.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 7 - file: g725027g12p13.jpg

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<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>8
<FILENAME>g725027g14p15.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 8 - file: g725027g14p15.jpg

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<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>9
<FILENAME>g725027g35o11.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 9 - file: g725027g35o11.jpg

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<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>10
<FILENAME>g725027g38r93.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 10 - file: g725027g38r93.jpg

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<TYPE>GRAPHIC
<SEQUENCE>11
<FILENAME>g725027g65b16.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 11 - file: g725027g65b16.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>12
<FILENAME>g725027g65y42.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 12 - file: g725027g65y42.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>13
<FILENAME>g725027g98u13.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 13 - file: g725027g98u13.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>14
<FILENAME>g725027leaf.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 14 - file: g725027leaf.jpg

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<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>15
<FILENAME>g725112photo_01mips.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 15 - file: g725112photo_01mips.jpg

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<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>16
<FILENAME>g725112sig_01mips.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 16 - file: g725112sig_01mips.jpg

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<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>17
<FILENAME>g725369dsp15.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 17 - file: g725369dsp15.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>18
<FILENAME>g725369dsp16.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 18 - file: g725369dsp16.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>19
<FILENAME>g725369dsp16a.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 19 - file: g725369dsp16a.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>20
<FILENAME>g725369dsp17.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 20 - file: g725369dsp17.jpg

</DOCUMENT>
</SEC-DOCUMENT>