The use of a trademark before it is declared invalid constitutes infringement. Paragraph 1 of Article 47 of the Trademark Law stipulates: "A registered trademark that has been declared invalid in accordance with the provisions of Articles 44 and 45 of this Law shall be announced by the Trademark Office, and the exclusive right to use the registered trademark shall be deemed as nonexistent from the beginning". According to the above provisions, the premise of non-infringement defense of post-registered trademark users is that their use behavior belongs to legal use. However, after the trademark is declared invalid, it should be regarded as nonexistent from the beginning, and the legal basis for the legitimate use of the trademark has been lost, so it is difficult to establish the claim that it should not bear tort liability, especially compensation liability. Paragraph 2 of Article 1 of the Provisions of the Supreme People's Court on Several Issues Concerning the Trial of Civil Disputes over Conflicts between Registered Trademarks and Enterprise Names stipulates that if the plaintiff files a lawsuit on the grounds that the registered trademark used by others on the approved goods is the same as or similar to its earlier registered trademark, the people's court shall inform the plaintiff to apply to the administrative competent authority for settlement in accordance with the provisions of Item 3 of Article 111 of the Civil Procedure Law.