legal ground
Article 18 of the Regulations on Household Registration
Citizens who change their names shall be handled in accordance with the following provisions:
(a) when a person under the age of 18 needs to change his name, his parents or adopters shall apply to the household registration authority for registration of change;
(two) when a person who has reached the age of eighteen needs to change his name, he shall apply to the household registration authority for registration of change.