You need to provide following documents if you get your visa processed in Italy:
1. Original passport which has more than six months left before it expires;
2. One completed Visa Application Form with a recently-taken passport photo stuck on it;
3. the original invitation letter issued by an authorized unit in China;
4. the return ticket or the hotel order;
5. the original and a copy of your permanent residence or work permit which should be valid for at least half a year.