Legal basis: People's Republic of China (PRC) Patent Law.
Article 19 If a foreigner, foreign enterprise or other foreign organization without a habitual residence or business office in China applies for a patent and handles other patent affairs in China, it shall entrust a patent agency established according to law to handle it.
Units or individuals applying for patents and handling other patent affairs in China may entrust a legally established patent agency to handle them.
Patent agencies shall abide by laws and administrative regulations, accept the entrustment of clients, and handle patent applications or other patent affairs; The contents of the client's invention and creation shall be kept confidential, except that the patent application has been published or announced. Specific measures for the administration of patent agencies shall be formulated by the State Council.
Article 20 Where any unit or individual applies to a foreign country for a patent for invention or utility model completed in China, it shall file a confidentiality review with the patent administration department of the State Council in advance. The procedures and time limit for confidentiality review shall be implemented in accordance with the provisions of the State Council.
Units or individuals in China may file an international patent application in accordance with the relevant international treaties to which People's Republic of China (PRC) is a party. The applicant who files an international application for a patent shall abide by the provisions of the preceding paragraph.
The patent administration department of the State Council shall handle international patent applications in accordance with the relevant international treaties to which People's Republic of China (PRC) is a party, this Law and the relevant provisions of the State Council.
Where an invention or utility model that violates the provisions of the first paragraph of this Article is applied for a patent in a foreign country, the patent right shall not be granted in China.