Ownership Submission
FORM 5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
Form 3 Holdings Reported
Form 4 Transactions Reported
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

ANNUAL STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

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 *
Moyer James C
 2. Issuer Name and Ticker or Trading Symbol
MONOLITHIC POWER SYSTEMS INC [MPWR] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief IC Design Engineer
(Last)
(First)
(Middle)

6409 GUADALUPE MINES ROAD		 3. Statement for Issuer's Fiscal Year Ended (Month/Day/Year)
12/31/2006
(Street)


SAN JOSE, CA 95120		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Reporting
(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 (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned at end of Issuer's Fiscal Year
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Amount (A) or (D) Price
Common Stock 05/10/2006   J(1) 1,496 D $ 0 1,359,572 D  
Common Stock 06/05/2006   J(2) 518,504 D $ 0 841,068 D  
Common Stock 05/11/2006   J(3) 43,255 D $ 0 86,953 I By F. Moyer 04 Trust
Common Stock 05/11/2006   G(4) 86,953 D $ 0 0 I By F. Moyer 04 Trust
Common Stock 05/11/2006   J(5) 43,255 D $ 0 86,953 I By J. Moyer 04 Trust
Common Stock 05/11/2006   G(6) 86,953 D $ 0 0 I By J. Moyer 04 Trust
Common Stock 06/05/2006   J(2) 518,504 A $ 0 518,504 I By Jointly w/Spouse
Common Stock 05/10/2006   J(1) 1,496 A $ 0 239,584 I by Moyer FamilyTrust
Common Stock 05/11/2006   J(7) 86,510 A $ 0 326,094 I by Moyer FamilyTrust

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 2270 (9-02)

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 (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 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
(Month/Day/Year)		 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 at End of Issuer's Fiscal Year
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
(A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Moyer James C
6409 GUADALUPE MINES ROAD
SAN JOSE, CA 95120		   X     Chief IC Design Engineer  

Signatures

James C. Moyer 02/01/2007
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Represents shares transferred from the reporting person's account to his family trust.
(2) Represents shares transferred from the reporting person's account to his joint account with his spouse.
(3) Represents shares transferred from the Frances K. Moyer 2004 Trust to the Moyer Family Trust.
(4) Gifted shares from the Frances K. Moyer 2004 Trust to the following: 10,811 shares to William C. & Viola J. Moyer Trust, Viola J. McCreary Moyer, Trustee; 38,071 shares to Cynthia Anne Moyer; and 38,071 to William James Moyer.
(5) Represents shares transferred from the James C. Moyer 2004 Trust to the Moyer Family Trust.
(6) Gifted shares from the reporting person's trust to the following: 10,811 shares to William C. & Viola J. Moyer Trust, Viola J. McCreary Moyer, Trustee; 38,071 shares to Cynthia Anne Moyer; and 38,071 to William James Moyer.
(7) Represents shares transferred from the James C. Moyer 2004 Trust and the Frances K. Moyer 2004 Trust.

Note: File three copies of this Form, one of which must be manually signed. If space provided is insufficient, see Instruction 6 for procedure.

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