From my infos:
1.Both parties need to apply to the marriage registration authority and fill out the “Marriage Registration Application Form”.
2.When applying, both parties should provide the following materials: copies of their valid identification documents such as ID cards and passports; their marriage application letters; three recent color passport-sized photos each.
3.If the materials are incomplete, a certificate letter from the marriage registration authority of their home country can be provided.
Fyi.tks