Procedure to authenticate my marriage certificate

You are supposed to get your marriage certificate authenticated from the China embassy in the Philippines. If you cannot do that in person, you can post it back and ask your friend or family to help you do that. First get it notarized by the local notary public and Regional Trial Court and the Philippines Ministry of Foreign Affairs; and then go to the embassy of China to get that attested; the required documents include your passport and its copy, the application form for attestation, and your marriage certificate and the copy as well as others.