1. The invention-creation for which the patent is applied involves national security or major interests;
2, the content of the patent application involves national defense interests;
3. Apply for other patents that need to be kept confidential.
legal ground
Article 4 of the patent law
Where the invention-creation for which a patent is applied involves national security or vital interests and needs to be kept confidential, it shall be handled in accordance with the relevant provisions of the state.
Article 19
Any unit or individual that applies to a foreign country for a patent for invention or utility model completed in China 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.