<SEC-DOCUMENT>0001287695-15-000325-index.html : 20150928
<SEC-HEADER>0001287695-15-000325.hdr.sgml : 20150928
<ACCEPTANCE-DATETIME>20150928101447
ACCESSION NUMBER:		0001287695-15-000325
CONFORMED SUBMISSION TYPE:	NSAR-B
PUBLIC DOCUMENT COUNT:		5
CONFORMED PERIOD OF REPORT:	20150731
FILED AS OF DATE:		20150928
DATE AS OF CHANGE:		20150928
EFFECTIVENESS DATE:		20150928

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:		NSAR-B
		SEC ACT:		1940 Act
		SEC FILE NUMBER:	811-07156
		FILM NUMBER:		151126422

	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>NSAR-B
<SEQUENCE>1
<FILENAME>mftcal.fil
<TEXT>
Document 1 - file: mftcal.fil

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.77I NEW SECUR
<SEQUENCE>2
<FILENAME>mft77i.htm
<TEXT>
Document 2 - file: mft77i.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.77Q1 OTHR EXHB
<SEQUENCE>3
<FILENAME>mft77q1a.htm
<TEXT>
Document 3 - file: mft77q1a.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.77Q1 OTHR EXHB
<SEQUENCE>4
<FILENAME>mft77q1d.htm
<TEXT>
Document 4 - file: mft77q1d.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.77B ACCT LTTR
<SEQUENCE>5
<FILENAME>munins577b.htm
<TEXT>
Document 5 - file: munins577b.htm

</DOCUMENT>
</SEC-DOCUMENT>