    <SEC-DOCUMENT>0001193125-17-221623-index.html : 20170705
    <SEC-HEADER>0001193125-17-221623.hdr.sgml : 20170705
    <ACCEPTANCE-DATETIME>20170705104241
    ACCESSION NUMBER:		0001193125-17-221623
    CONFORMED SUBMISSION TYPE:	N-CSR
    PUBLIC DOCUMENT COUNT:		23
    CONFORMED PERIOD OF REPORT:	20170430
    FILED AS OF DATE:		20170705
    DATE AS OF CHANGE:		20170705
    EFFECTIVENESS DATE:		20170705

    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-CSR
    		SEC ACT:		1940 Act
    		SEC FILE NUMBER:	811-07642
    		FILM NUMBER:		17946464

    	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-CSR
    <SEQUENCE>1
    <FILENAME>d385352dncsr.htm
    <DESCRIPTION>BLACKROCK MUNIASSETS FUND, INC
    <TEXT>
    Document 1 - file: d385352dncsr.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.CERT
    <SEQUENCE>2
    <FILENAME>d385352dex99cert.htm
    <DESCRIPTION>CERTIFICATION PURSUANT TO SECTION 302
    <TEXT>
    Document 2 - file: d385352dex99cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.906CERT
    <SEQUENCE>3
    <FILENAME>d385352dex99906cert.htm
    <DESCRIPTION>CERTIFICATION PURSUANT TO SECTION 906
    <TEXT>
    Document 3 - file: d385352dex99906cert.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.PROXY.POL
    <SEQUENCE>4
    <FILENAME>d385352dex99proxypol.htm
    <DESCRIPTION>CLOSED-END FUND PROXY POLICY
    <TEXT>
    Document 4 - file: d385352dex99proxypol.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.CORP.GOVN
    <SEQUENCE>5
    <FILENAME>d385352dex99corpgovn.htm
    <DESCRIPTION>GLOBAL CORPORATE GOVERNANCE & ENGAGEMENT PRINCIPLES
    <TEXT>
    Document 5 - file: d385352dex99corpgovn.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>6
    <FILENAME>g384140dsp010.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 6 - file: g384140dsp010.jpg

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    <SEQUENCE>7
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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 7 - file: g384140g07l90.jpg

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    <SEQUENCE>8
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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 8 - file: g384140g24s47.jpg

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    <SEQUENCE>9
    <FILENAME>g384140g80s99.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 9 - file: g384140g80s99.jpg

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    <DOCUMENT>
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    <SEQUENCE>10
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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: g384140g98u13.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>g385352g09g62.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: g385352g09g62.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>12
    <FILENAME>g385352g09h65.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 12 - file: g385352g09h65.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>g385352g41l68.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 13 - file: g385352g41l68.jpg

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    <SEQUENCE>14
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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 14 - file: g385352g44u23.jpg

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    <SEQUENCE>15
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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 15 - file: g385352g51n99.jpg

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    <TYPE>GRAPHIC
    <SEQUENCE>16
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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 16 - file: g385352g60p62.jpg

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    <SEQUENCE>17
    <FILENAME>g385352g62e83.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 17 - file: g385352g62e83.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>g385352g65b16.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 18 - file: g385352g65b16.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>g385352g83y23.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 19 - file: g385352g83y23.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>g385352g98u13.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 20 - file: g385352g98u13.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>21
    <FILENAME>g385352leaf.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 21 - file: g385352leaf.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>22
    <FILENAME>g385942photo_01mips.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 22 - file: g385942photo_01mips.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>23
    <FILENAME>g385942sig_01mips.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 23 - file: g385942sig_01mips.jpg

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