1. Original passport which has more than 6 months left before it expires from the date of application and sufficient blank visa pages.
2. One completed Visa Application Form
3. a recently-taken passport photo
4. Visa notification issued by an authorized unit in China.Or invitation letter from the legally registered company in China.
5.Covering letter from applicant's company or office with the details of the visiting purpose.
6. Photocopy of the personal data page of applicant’s passport.
You'd better provide your used China visas when you submit your application.