Aliens applying for the extension of their Chinese residence permit shall submit an application to the exit and entry administration of the public security organ of the local people’s government at or above the county level 30 days before the expiration of the validity of their residence permit. For example, if the residence permit expires on November 30th, you can apply for an extension on or after November 1st. It is recommended to plan the time in advance and prepare relevant materials to avoid affecting the legal residence in China.