The principle of priority is one of the principles of patent application. Including foreign priority and domestic priority. The main content of the right of priority is that if an applicant files an application for a patent for the same subject matter in China within twelve months from the date of the first filing of an application for a patent for invention or utility model in a foreign country, or within six months from the date of the first filing of an application for a patent for design in a foreign country, he or she shall, in accordance with an agreement concluded between that foreign country and China or an international treaty to which both countries are parties, Or they may enjoy priority according to the principle of mutual recognition of priority. The applicant may enjoy the right of priority if, within 12 months from the date when he first filed an application for a patent for invention or utility model in China, he or she files another application for a patent on the same subject with the patent administration department under the State Council. The former is a foreign priority, and the latter is a domestic priority. The two are different in the applicable patent type and application location. The practical significance of priority is that the date of the first patent application is taken as the time standard to judge the novelty. The date of the first application is called the priority date, and the above specific period is called the priority period. Where the applicant claims the right of priority, he/she shall make a written declaration at the time of application and submit a copy of the patent application document first filed within three months; Where no written declaration is made or the copies of the patent application documents are not submitted within the time limit, the right of priority shall be deemed not to have been claimed. When the first application is abandoned or rejected, its priority still exists. The right of priority may be transferred, that is, it may be transferred together with the right of patent application. For example, if A applied for a patent for invention in the United States on October 31, 2006, and then filed a patent application for the same subject in China on October 20, 2007, in accordance with the agreement signed between the United States and China or the international treaty to which both countries are parties, or in accordance with the principle of mutual recognition of priority, China took the date of its application in the United States, i.e. October 31, 2006, as the date of its application to China. If someone applied for a patent on the same subject in China between October 31, 2006 and October 20, 2007, the China Patent Office will not accept it. This is foreign priority. As for domestic priority, the same reason is not given here. I believe you can understand.