Abstract: Media surveillance can greatly supplement national surveillance system of infectious disease and public health emergencies.In the internet era, people disseminate information quickly through network media and social media, which have become important sources of information for detecting disease outbreak, early warning and emergency preparedness.The article systematically summarizes the development of media surveillance in public health event surveillance home and abroad with supporting cases, summing up 3 modes of media surveillance and illustrating its role in early warning and forecasting incidents as well as feedback of response.Meanwhile, the article points out that media surveillance is restricted by internet use, media guidance and searching habits, and proposes that media surveillance based on internet could be integrated into present surveillance system.