In order to standardize the priority monitoring of medical device adverse events, and guide the monitoring agencies and medical institutions at all levels to monitor the sentinel and the marketing license holders to carry out priority monitoring work, and formulate the guiding principles in accordance with the “Administrative Measures for Monitoring and Reassessing Medical Device Adverse Events”. The priority monitoring of medical device adverse events (hereinafter referred to as priority monitoring) refers to the staged monitoring activities initiated to study the risk status, characteristics, severity and occurance rate of a certain medical device variety or product after listing.