Statute of limitations rules in patent infringement litigation in China.

This article focuses on the statute of limitations for patent infringement actions in China, particularly following the 2020 fourth amendment to the Chinese Patent Law, which established a three-year limitation period aligned with the Civil Code. It discusses unresolved issues such as when the limitation period begins, how knowledge of infringement and infringers is proven, and the applicable limitation period for infringements occurring before the amendment. The article highlights judicial practices in determining the start of the limitation period, including reliance on evidence preservation dates and the challenges in proving constructive knowledge. It also addresses the legal effects of the statute of limitations defense, the interruption of limitation periods, and conflicts arising from legislative transitions between different laws. The article concludes by emphasizing the need for clearer legislative and judicial guidance to balance patent holders’ rights with the interests of third parties and potential non-wilful infringers.