Getting Married in Hong Kong
The minimum legal age for marriage in Hong Kong is 16 years of age (Gregorian reckoning). You can choose to register for marriage in Hong Kong regardless of where you live or what your nationality is.
The following website provides information on marriage registration, including giving the notice of intended marriage on the prescribed form in Hong Kong or from places outside Hong Kong, celebrating your marriage in different venues as well as post-registration of marriage taken place before 7 October 1971:
GovHK - Marriage Registration
Getting Married in the Mainland
If you plan to get married with your partner in the Mainland, you have to go through marriage registration procedures in accordance with Mainland laws and regulations. Marriage registration in the Mainland is the duty of the home affairs offices of the governments of provinces, autonomous regions and municipalities, or the authorities designated by the home affairs offices.
You may refer to the website of the Shanghai Civil Affairs Bureau for a guide to marriage registration for Shanghai and Hong Kong residents, policy papers and information about the institutions responsible for the registration. For information on the required procedures and documents for marriage registration by governments of other provinces, autonomous regions and municipalities, please contact the relevant marriage registration authorities.