I'm from Somalia but live n have italia permit residence I need Visa for PRC.How to apply it?

You go to PRC for sightseeing purpose, right? If yes, you should first prepare those documents containing your passport and ots photocopy, the filled-out application form affixed with a passport-sized color photo, round trip air tickets and hotel booking record, as well as your residence permit in Italy and other materials the consular officers consider necessary.
And then submit your application to the CVASC to apply for it.