If an invention-creation wants to obtain patent protection in other countries or regions in addition to obtaining a patent right in its own country, it must file a patent application in the country or region that wants to obtain patent protection, and the right to grant a patent belongs to the patent administration department of that country or region. The applicant can file a patent application to a foreign country according to the Paris Convention, that is, the applicant needs to submit a separate patent application to each country or region that he wants to seek protection; Alternatively, according to the provisions of PCT, an application (international application) filed by an applicant in one language in one place can take effect in several countries, instead of filing patent applications in several countries and/or regions respectively.
According to the principle of patent independence of the Paris Convention, patent rights are regional, that is, the patent rights granted by a country according to its own patent law are only valid within its jurisdiction and are not binding on other countries, and foreign countries do not undertake the obligation to protect their patent rights. Therefore, American patents cannot be protected in China. If you want to apply for a U.S. patent in China, I suggest you search for relevant China patents or other foreign patents that have been applied for or are being applied for in China, so as to avoid infringement when you use the U.S. patent in China.