I am permanent resident of Australia, do I need visa to visit Hong Kong ? i have Vietnam passport

Kelly, I'm afraid you still need it. You can apply for the HK entry permit at the embassy or consulate in Australia or send the application documents to the HK Immigration Department directly. You will need th following documents: application form ID 1003A, your recent photograph affixed on the application form, photocopy of your passport, photocopy of your financial standing proof, e.g. bank statements, savings accounts passbooks, tax receipts, etc. and proof of employment (if any), e.g. company leave letter, salary slips, etc., photocopy of transportation tickets, and photocopy of proof that can justify your purpose for visiting Hong Kong.

Tks Grace.please advise can I apply online. If yes which website I should use.

Kelly, no online service is provided.