Legal basis: Article 23 of the Provisions of the Supreme People's Court on the Applicable Law in the Trial of Patent Dispute Cases has a limitation of action of two years, counting from the date when the patentee or interested party knows or should know about the infringement. If the obligee has sued for more than two years, and the infringement is still going on at the time of prosecution, the people's court shall order the defendant to stop the infringement within the validity period of the patent right, and the amount of infringement damages shall be calculated within two years from the date when the obligee files a lawsuit with the people's court.