1992 The revised Patent Law shall come into force as of 1993 1.
Therefore, the protection period of the invention patent authorized after 1993 is 20 years, counting from the date of application.
In addition, according to Announcement No.80 of China National Intellectual Property Administration, the invention patent right filed in the former China Patent Office before 1992 12 3 1 and valid until 200121is extended to 20 years from the date of application.