Patent applications can only be submitted in China National Intellectual Property Administration, and can be submitted by post or in person. China National Intellectual Property Administration Patent Office accepts patent applications, and local offices can also accept patent applications. The specific location can be found on the website of the State Knowledge Bureau.
Patent application is a highly professional matter, which will affect whether it is authorized or not and the scope of protection after authorization. It is recommended to find a professional patent agency to consult the application.