Abstract: Shanghai is a super-large metropolis with a highly developed globalization. Since the 21st century， Shanghai has experienced several threats of emerging and imported infectious diseases. Infectious disease surveillance has been established and developed from single-disease surveillances to a comprehensive surveillance network. Integration of clinical and preventive medicine has been gradually extended， which facilitates the improvement in the monitoring and early warning system. In 2020， when the COVID-19 epidemic spread， Shanghai quickly established a prevention and control expert team and a clinical medical expert team to effectively and shortly control local COVID-19 epidemic. In order to improve Shanghai’s capacity to respond to major epidemics of infectious diseases and public health emergencies， the metropolis will build and improve a three-level diagnosis and treatment system for emerging， imported， rare， and unknown infectious diseases in the next five years. Based on the big data monitoring platform of medical institutions， Shanghai will achieve the intelligence-supported diagnosis and treatment of infectious diseases， and consolidate the cooperation to implement the integration of clinical and preventive medicine.