legal ground
Article 31 of the Regulations for the Implementation of the Trademark Law
Where a registered trademark is assigned, the assignor and the assignee shall submit an application for assignment of the registered trademark to the Trademark Office. The application procedures for the assignment of a registered trademark shall be handled by both the assignor and the assignee. Where the Trademark Office approves an application for the transfer of a registered trademark, it shall issue a corresponding certificate to the transferee and make an announcement.
Where a registered trademark is transferred, if the trademark registrant fails to transfer the same or similar trademarks registered on the same or similar goods together, the Trademark Office shall notify him to make corrections within a time limit; If it fails to make corrections within the time limit, it shall be deemed as giving up the application for transferring the registered trademark, and the Trademark Office shall notify the applicant in writing.