want to know about F type Visa

It's possible for you to extend your current F type at the exit and entry administration of the local PSB within China. Usually, the extended period won’t exceed the duration of stay of your current F type. You need to prepare the relevant documents including your passport and copy of its data page, valid registration form of temporary residence, a fully filled-out application form affixed with a passport-style photo, and an invitation letter as well as the return ticket.