Exhibit 99.1350CERT


     Certification Pursuant to Rule 30a-2(b) under the 1940 Act and
                  Section 906 of the Sarbanes Oxley Act


Pursuant to 18 U.S.C.  1350, the undersigned officer of BlackRock Municipal
Bond Fund, Inc. (the "Registrant"), hereby certifies, to the best of his
knowledge, that the Registrant's Report on Form N-CSR for the period ended
June 30, 2007, (the "Report") fully complies with the requirements of Section
15(d) of the Securities Exchange Act of 1934, as amended, and that the
information contained in the Report fairly presents, in all material respects,
the financial condition and results of operations of the Registrant.


Date: August 20, 2007


/s/ Robert C. Doll, Jr.
- ------------------------
Robert C. Doll, Jr., Chief Executive Officer of
BlackRock Municipal Bond Fund, Inc.


Pursuant to 18 U.S.C.  1350, the undersigned officer of BlackRock Municipal
Bond Fund, Inc. (the "Registrant"), hereby certifies, to the best of his
knowledge, that the Registrant's Report on Form N-CSR for the period ended
June 30, 2007, (the "Report") fully complies with the requirements of Section
15(d) of the Securities Exchange Act of 1934, as amended, and that the
information contained in the Report fairly presents, in all material respects,
the financial condition and results of operations of the Registrant.


Date: August 20, 2007


/s/ Donald C. Burke
- -------------------
Donald C. Burke, Chief Financial Officer of
BlackRock Municipal Bond Fund, Inc.



This certification is being furnished pursuant to Rule 30a-2(b) under the
Investment Company Act of 1940, as amended, and 18 U.S.C. Section 1350 and is
not being filed as part of the Form N-CSR with the Securities and Exchange
Commission