    <SEC-DOCUMENT>0001193125-20-001173-index.html : 20200103
    <SEC-HEADER>0001193125-20-001173.hdr.sgml : 20200103
    <ACCEPTANCE-DATETIME>20200103112919
    ACCESSION NUMBER:		0001193125-20-001173
    CONFORMED SUBMISSION TYPE:	N-CSRS
    PUBLIC DOCUMENT COUNT:		15
    CONFORMED PERIOD OF REPORT:	20191031
    FILED AS OF DATE:		20200103
    DATE AS OF CHANGE:		20200103
    EFFECTIVENESS DATE:		20200103

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			BLACKROCK MUNIASSETS FUND, INC.
    		CENTRAL INDEX KEY:			0000901243
    		IRS NUMBER:				223239638
    		STATE OF INCORPORATION:			MD
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		N-CSRS
    		SEC ACT:		1940 Act
    		SEC FILE NUMBER:	811-07642
    		FILM NUMBER:		20503871

    	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:	MUNIASSETS FUND INC
    		DATE OF NAME CHANGE:	19930714

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	MUNIINCOME FUND INC
    		DATE OF NAME CHANGE:	19930517
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>N-CSRS
    <SEQUENCE>1
    <FILENAME>d799892dncsrs.htm
    <DESCRIPTION>BLACKROCK MUNIASSETS FUND, INC
    <TEXT>
    Document 1 - file: d799892dncsrs.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.CERT
    <SEQUENCE>2
    <FILENAME>d799892dex99cert.htm
    <DESCRIPTION>CERTIFICATIONS PURSUANT TO SECTION 302
    <TEXT>
    Document 2 - file: d799892dex99cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.906 CERT
    <SEQUENCE>3
    <FILENAME>d799892dex99906cert.htm
    <DESCRIPTION>CERTIFICATIONS PURSUANT TO SECTION 906
    <TEXT>
    Document 3 - file: d799892dex99906cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>4
    <FILENAME>g798985photo_01mips.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 4 - file: g798985photo_01mips.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>5
    <FILENAME>g798985sig_01mips.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 5 - file: g798985sig_01mips.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>g799892g09g62.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: g799892g09g62.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>7
    <FILENAME>g799892g09h65.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: g799892g09h65.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>8
    <FILENAME>g799892g41l68.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: g799892g41l68.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>9
    <FILENAME>g799892g42l24.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: g799892g42l24.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>10
    <FILENAME>g799892g44u23.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: g799892g44u23.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>g799892g51n99.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: g799892g51n99.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>g799892g60p62.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: g799892g60p62.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>g799892g62e83.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: g799892g62e83.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>g799892g83y23.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: g799892g83y23.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>g799892leaf.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: g799892leaf.jpg

    </DOCUMENT>
    </SEC-DOCUMENT>