How do I get a visa for China? just visit for 16 days and I'm a resident in USA not citizen.

You should go the consulate-general which has jurisdiction over your residence and submit the required materials to apply for a L type. The materials include yor passport, a photcopy of the passport's data page, an application form, a recent taken color photo, the original and photocopy of your resident card, and roundtrip tickets and hotel booking records.