According to Article 20 1 of the Patent Law of People's Republic of China (PRC):
After an individual or unit completes an invention-creation, it may first file a national application with the Chinese Patent Office. Then, an international application is filed within the priority period and priority is requested. In this way, during the priority period, the applicant considers whether it is necessary to apply for a patent in a foreign country, how to apply, and make necessary preparations for filing an application.
Extended data:
China units (including foreign-funded enterprises) or individuals applying to foreign countries for patents for inventions and creations completed in China shall meet the following three conditions:
First, you should first apply for a patent in China National Intellectual Property Administration, China, or submit an international application to China National Intellectual Property Administration or the International Bureau of the World Intellectual Property Organization to designate China;
The second is to entrust foreign-related institutions;
Third, if an invention involves national security or vital interests and needs to be kept confidential, it cannot apply for a patent from a foreign country, but only from China.
Baidu Encyclopedia-People's Republic of China (PRC) Patent Law (Laws and Regulations)