Abstract: Objective To investigate the epidemiological trend of class A and class B infectious diseases from 1953 to 2008 in Songjiang district to provide scientific basis for making the following preventive and control stra tegy. Methods Descriptive epidemiology was used to analyze the data of class A and class B infectious diseases from 1953 to 2008. Results For more than 50 years, the average mortality rates of class A and B infectious diseases went down gradually in Songjiang district. During the years of 1950 to 1960, respiratory diseases, infectious diseases with natural foci and insect - borne infectious diseases took the leading decline position, while gastro - intestinal infections accounted for the largest part of all infectious diseases since year 1970. Sexually transmitted diseases and tuberculosis increased remarkably after the 90's, class A infectious diseases, planned immunization related diseases, diseases with natural foci and insect - borne infectious diseases were effectively controlled or eliminated and many in- fectious diseases have been controlled completely. Conclusion Infectious diseases prevention and control work of Songjiang district have achieved remarkable results, but some new characteristics of infectious diseases are emerging and the control and prevention situation is still very grim. So it is quite necessary to develop and refine strategies, enhance preventive work infrastructure and improve the level of disease prevention and monitoring to prevent infectious disease.