Do make sure that you keep at least 2 photocopies of your important documents. You should consider having your important documents, such as medical prescriptions and marriage certificates(if necessary), translated into Mandarin before leaving your country.    

Below is the checklist of important documents that you must carry with you to Beijing.
Valid passport and visa
•Admission Letter from Peking University (original copy)
•Visa Application for Study in China form (also known as the JW201/JW202 form) (original)
•2-inch full-faced photos with white background (at least 2 copies)
•Physical examination record and blood test reports (original, if available)
•Passport, visa, marriage certificate and birth certificates of your family members (if any)

You may also consider bringing these documents with you if you deem them necessary:
•School transcripts
•Graduation certificate
•Reference/Recommendation letters