Report of Foreign Issuer (6-k)

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 May 2015

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Commission File Number: 001-32371

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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 ¨

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):________________

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):________________

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: May 12, 2015

Exhibit Index

Exhibit 99.1 – Press Release

Exhibit 99.1

Sinovac to Participate in UBS Global Healthcare Conference

BEIJING, May 12, 2015 -- Sinovac Biotech Ltd. (NASDAQ:SVA), a leading provider of biopharmaceutical products in China, today announced that the Company’s management will present at the UBS Global Healthcare Conference from 11:30 AM to 12:00 AM on May 20, 2015, the conference will be held at the Sheraton New York Times Square Hotel in New York City. Please contact your UBS representative for conference registration information and to schedule a meeting with the Company.

About Sinovac

Sinovac Biotech Ltd. is a China-based biopharmaceutical company that focuses on the research, development, manufacturing, and commercialization of vaccines that protect against human infectious diseases. Sinovac's product portfolio includes vaccines against hepatitis A and B, seasonal influenza, H5N1 pandemic influenza (avian flu), H1N1 influenza (swine flu), mumps and canine rabies. In 2009, Sinovac was the first company worldwide to receive approval for its H1N1 influenza vaccine, which it has supplied to the Chinese Government's vaccination campaign and stockpiling program. The Company is also the only supplier of the H5N1 pandemic influenza vaccine to the government stockpiling program. Sinovac has filed a new drug application with the China Food & Drug Administration for its proprietary enterovirus 71 vaccine, having been proven effective in preventing hand, foot and mouth disease in infants and children during its Phase III clinical trial. The Company is currently developing a number of new products including a Sabin-strain inactivated polio vaccine, pneumococcal polysaccharides vaccine, pneumococcal conjugate vaccine and varicella vaccine. Sinovac primarily sells its vaccines in China, while also exploring growth opportunities in international markets. The Company has exported select vaccines toMexico, Mongolia, Nepal, and the Philippines, and was recently granted a license to commercialize its hepatitis A vaccine in Chile. For more information, please visit the Company's website at www.sinovac.com.

Contact

Sinovac Biotech Ltd.
Helen Yang / Chris Lee
Tel: +86-10-8279-9659 / 9696
Fax: +86-10-6296-6910
Email: ir@sinovac.com

ICR Inc.
Bill Zima
U.S: 1-646-308-1707
Email: william.zima@icrinc.com