The paper dilates on the design ideas, overall architecture and major functions of the active disease surveillance system based on the regional health information platforms of prefecture-level cities, including syndromic surveillance, surveillance on notifiable infection diseases, surveillance on chronical diseases, statistical analysis and report management and so on, carries out discussions about the application effects and existing problems of the system, and points out that the system is conducive to the reduction of the rate of failing to report, the enhancement of the quality and efficiency of disease surveillance.