Sec Form 4 Filing - Lazar Michael B @ BlackRock Kelso Capital CORP - 2010-03-15

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Lazar Michael B 2. Issuer Name and Ticker or Trading Symbol BlackRock Kelso Capital CORP [ BKCC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) X __ Other (specify below) Chief Operating Officer/C.O.O of investment adviser (Last) (First) (Middle) C/O BLACKROCK KELSO CAPITAL CORPORATION, 40 EAST 52ND STREET 3. Date of Earliest Transaction (MM/DD/YY) 03/15/2010 (Street) NEW YORK, NY10022 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, par value $0.001 per share 03/15/2010 A 68,662 ( 1 ) A $ 0 ( 1 ) 213,049.87 ( 2 ) D Common Stock, par value $0.001 per share 40,553.68 I By Michael B. Lazar IRA ( 3 ) Common Stock, par value $0.001 per share 42,493.31 I By BlackRock Kelso Capital Advisors LLC ( 4 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Lazar Michael B C/O BLACKROCK KELSO CAPITAL CORPORATION 40 EAST 52ND STREET NEW YORK, NY10022 Chief Operating Officer C.O.O of investment adviser Signatures Michael B. Lazar, by Frank D. Gordon, Attorney-in-Fact 03/16/2010 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Restricted Shares granted by BlackRock Kelso Capital Advisors LLC ("Advisor") pursuant to a Restricted Stock Agreement, dated March 15, 2010, vesting in equal installments on January 2, 2011, 2012 and 2013. ( 2 )Includes 6,058.56 Restricted Shares granted by Advisor pursuant to a Restricted Stock Agreement, dated December 31, 2007, vesting on January 2, 2011; and 15,781 Restricted Shares granted by Advisor pursuant to a Restricted Stock Agreement, dated January 2, 2009, vesting in equal installments on January 2, 2011 and 2012. Excludes shares owned indirectly by a family trust. The individual disclaims beneficial ownership of the shares owned by the trust. ( 3 )Includes shares owned indirectly by an individual retirement account as to which the Reporting Person is the beneficiary. ( 4 )The Reporting Person, as a Manager of Advisor, may be deemed to beneficially own all the Common Stock of the Issuer owned by Advisor. The Reporting Person disclaims benefical ownership of such shares except to the extent of his pecuniary interest therein and the inclusion of such shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or otherwise.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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