i got GW letter from university of south china so which documents are required for China X visa?

You need to provide the original passport and a copy of its pages with personal information. Visa Application Form V2011A with your signature, a passport-sized photo, the original JW-201 or JW-202 form and a photocopy, and the original admission letter and a copy, as well as the original Foreigner Physical Examination Form with a hospital's official stamp and a photocopy.