Mrs.oghogho, you need to apply for L visa for family visit, please submit the visa application according to consular districts, if your residence is under the consular jurisdiction of China Embassy in Rome, you have to submit the visa application to Chinese Visa Application Service Center in Rome:
Address: Viale Regina Margherita 279, 00198 Roma
Tel: 06-44250240 　　
Fax：06-44260770　　
Email：romacentre visaforchina.org　　
website：www.visaforchina.it　　

as for the requirements:
1. your passport valid for at least six months with at least 2 blank visa pages.
2. Italian residence permit and its copy
3. Application form: All applicants should fill in one visa application form appropriately and authentically
4. One recent passport size photograph
5. round-trip flight tickets
6. invitation letter from your sister, the copy of her residence permit in China, and kinship certificate