F Visa: Issued to a foreigner who is invited to China for a visit, an investigation, a lecture, to do business, scientific-technological and culture exchanges, short-term advanced studies or intern practice for a period of no more than six months.
To apply F visa, you should provide:
one completed visa application form
one recent photo with size 48m* 33mm (passport photo)
valid passport with validity of six months at least
invitation letter from Chinese authorities or entities, or notification letter from Chinese authentic authorities.
alltså räcker det om du inte ska vara där längre än 6 månader.
http://www.chinaembassy.se/eng/qzhhz/conservice/qz/t374505.htm