Lawyer Ma Yingqiu’s answer: Hello, regarding the statute of limitations for patent litigation, the statute of limitations for the patentee’s request to pay royalties is two years from the publication of the invention patent application to the granting of the patent right. The calculation starts from the date when it becomes known that others are using the invention. However, if the patentee has known or should have known about it before the date when the patent right is granted, the calculation starts from the date when the patent right is granted. The Patent Law of the People's Republic of China stipulates that the statute of limitations for infringement of patent rights is two years, starting from the date when the patentee or interested party learns or should have learned of the infringement. The judicial interpretation of the "Several Provisions on Applicable Legal Issues in the Trial of Patent Dispute Cases" of the People's Republic of China and the Supreme People's Court of the People's Republic of China stipulates that "the statute of limitations for infringement of patent rights is two years. If the right holder files a lawsuit more than two years after becoming aware of the infringement, if the infringement continues at the time of prosecution, the people's court shall order the defendant to cease the infringement and compensate for the infringement during the validity period of the patent. The amount should be calculated forward two years from the date the right holder files a lawsuit with the People's Court. "That is to say, if the right holder files a lawsuit after the two-year statute of limitations, if the patent right is within the validity period, the People's Court should still order the defendant to stop infringement. According to the law, compensation claims can be calculated forward two years from the date of filing of the lawsuit. That is, the parts exceeding two years will not be supported. Those after the two-year statute of limitations should still be adjudicated to ensure the rights and interests of the patentee and the punishment of infringers.