legal ground
Article 39 of the Trademark Law of People's Republic of China (PRC)
The period of validity of a registered trademark is ten years, counting from the date of approval of registration.
Article 40
Where a registered trademark needs to be used continuously after the expiration of its term of validity, the trademark registrant shall go through the renewal procedures in accordance with the provisions within 12 months before the expiration; If it has not been handled during this period, it can be extended for six months. The validity period of each renewal registration is ten years, counting from the day after the last expiration of the trademark. If the renewal formalities are not completed at the expiration of the period, the registered trademark shall be cancelled. The Trademark Office shall announce the renewed registered trademark.
Article 41
Where a registered trademark needs to change the name, address or other registered items of the registrant, an application for change shall be filed.