The Measures clarifies the main responsibilities of the medical device marketing authorization holder. Based on basic requirements, individual adverse events, group adverse events and periodic risk assessment and reporting, it specifies the time limits, procedures and requirements for reporting and assessment, details risk control requirements for the holder, stipulates that the holder should take the initiative to conduct reassessment and tightens the supervision and inspection by the drug regulatory authorities, as well as increases the severity of the punishment for violations of laws and regulations. The Measures improves the surveillance system of adverse events and lays stress on the obligation of the holder to directly report adverse events. The Measures tightens the risk control requirements and stipulates that the holder shall take relevant measures including stopping production, implementing recalls and modifying manuals and promptly announce the risks and disposal of them related to safety in use of medical devices when the holder is aware of unreasonable risks possibly threatening human health and life safety. The Measures establishes a key surveillance system, clarifying that the drug regulatory authorities above the provincial level can designate organizations meeting certain qualifications as the surveillance sentinels to actively collect the surveillance data of key surveilled varieties of devices. The Measures improves the reassessment system, defines the main responsibility of the holder to carry out reassessment on its own initiative, requiring that the holder shall take the initiative to perform reassessment and, if the reassessment results indicate product defects that endanger personal safety or unacceptable risk-benefit ratio, apply for cancellation of product marketing and make the same known to the public in a timely manner. The Measures tightens supervision and inspection and strict investigation on and punishment for illegal acts of failure to fulfill the responsibility of direct reporting, requiring the provincial-level drug regulatory authorities to formulate inspection plans, define inspection priorities and carry out supervision and inspection on the construction and implementation of the holders' adverse event surveillance system.