legal ground
Article 12 of the Patent Law of People's Republic of China (PRC)
Any unit or individual that exploits another person's patent shall conclude an exploitation license contract with the patentee and pay the patentee the royalties. The licensee has no right to allow any unit or individual other than those stipulated in the contract to exploit the patent.
Article 13
After the publication of an application for a patent for invention, the applicant may require the entity or individual who exploits the invention to pay an appropriate fee.