Legal analysis: after the patent is granted, according to the law, the protection period of the invention is 20 years, the utility model is 10 year, and the design is 15 year, counting from the date of application. Protection expired and cannot be renewed. However, in fact, the annual fee must be paid on schedule every year in order to maintain the correct status. You can also choose to pay in advance for several years at one time, but most ordinary patents choose to renew once a year. If you don't pay the annual fee on time, it is equivalent to giving up this patent right. If the annual fee is paid on schedule every year, but after the legal period, such as 20 years of invention, the patent will be completely invalid.
Legal basis: Articles 13 and 45 of the Decision of NPC Standing Committee on Amending the Patent Law of People's Republic of China (PRC) are amended as: "The term of invention patent is 20 years, and the term of utility model patent and design patent is 10 year, all of which are counted from the date of filing."