What should I do if I am complained of patent infringement?

First of all, we must judge whether our products are within the scope of patent protection. Secondly, if the product really belongs to the scope of patent protection, it is necessary to judge whether the patent right is stable. If the patent does not meet the conditions for granting a patent after retrieval and analysis, it may file an invalid procedure with the Patent Office. Finally, if the patent right is stable, the product belongs to the scope of protection, and the defendant has no subjective intention of infringement, he should provide evidence such as legal source and prior use to prove that he has no subjective intention. Article 70 of China's Patent Law stipulates that anyone who uses, promises to sell or sells an infringing patented product for production and business purposes without knowing that it was manufactured and sold without the permission of the patentee shall not be liable for compensation. Article 59 of People's Republic of China (PRC) Patent Law, Article 60 of People's Republic of China (PRC) Patent Law and Article 70 of People's Republic of China (PRC) Patent Law.