UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 UNDER

THE SECURITIES EXCHANGE ACT OF 1934

For the month of January 2010

Commission File Number: 001-32371

SINOVAC BIOTECH LTD.

No. 39 Shangdi Xi Road

Haidian District

Beijing 100085, People’s Republic of China

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F x Form 40-F o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): o

Incorporation by Reference

This 6-K shall be incorporated by reference into the Registrant’s Registration Statement on Form F-3 as filed on November 18, 2009 (No. 333- 333-163165).

The Registrant is filing material documents not previously filed.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	SINOVAC BIOTECH LTD.


	By:	/s/ Weidong Yin
	Name: Weidong Yin
	Title: Chairman and Chief Executive Officer

Date: January 28, 2010

Exhibit Index

Exhibit 1.1 – Underwriting Agreement dated January 27, 2010 among the Company, UBS Securities LLC and Piper Jaffray & Co., as managing underwriters and representatives of the several underwriters