Legal analysis: The time for defense of a trademark invalidation declaration is within thirty days. In addition, the trademark management department should process the application for a relevant trademark invalidation declaration within nine months. The specific situation should be based on the actual situation. Legal determination to avoid errors in legal application. When the Trademark Office makes a decision to declare a registered trademark invalid, it shall notify the parties concerned in writing. If the party concerned is dissatisfied with the decision of the Trademark Office, he may apply to the Trademark Review and Adjudication Board for review within fifteen days from the date of receipt of the notice.

Legal basis: "Trademark Law of the People's Republic of China" Article 34 For a trademark that rejects the application and refuses to be announced, the Trademark Office shall notify the trademark registration applicant in writing. If the trademark registration applicant is dissatisfied, he may apply to the Trademark Review and Adjudication Board for review within fifteen days from the date of receipt of the notice. The Trademark Review and Adjudication Board shall make a decision within nine months from the date of receipt of the application and notify the applicant in writing. If there are special circumstances that require an extension, it can be extended for three months with the approval of the industrial and commercial administration department of the State Council. If the party concerned is dissatisfied with the decision of the Trademark Review and Adjudication Board, it may file a lawsuit with the People's Court within thirty days from the date of receipt of the notice.