China's patent law stipulates that the effective date of the invention patent is

According to the provisions of Articles 39 and 40 of the Patent Law of People's Republic of China (PRC), the patent right shall come into effect as of the date when the patent administrative department of the State Council issues a patent certificate and makes an announcement.

People's Republic of China (PRC) Patent Law (revised in 2008)

Article 39 If the application for a patent for invention is not found to be rejected after substantive examination, the administrative department for patent in the State Council shall make a decision to grant a patent right for invention, issue a patent certificate for invention, and register and announce it at the same time. The invention patent right shall take effect as of the date of announcement.

Article 40 If the application for a patent for utility model or design is not found to be rejected after preliminary examination, the administrative department for patent in the State Council shall make a decision to grant the patent right for utility model or design, issue the corresponding patent certificate, and register and announce it at the same time. The patent right for utility model and the patent right for design shall take effect as of the date of announcement.

Article 42 The term of patent right for invention is 20 years, and the term of patent right for utility model and patent right for design is 10 years, counting from the date of application.