Abstract: Objective The present study was designed to evaluate the adverse events that were likelv to occur after vaccination with the available vaccines in order to provide essential data for the administrations to formulate the compensations，which suit the actual conditions of Hangzhou，for the adverse events caused by vaccinations．Methods The data from passive surveillance in 2004 were used tO analyze the incidences of adverse events caused by different vaccines and compare the incidences of adverse events caused by the preparations for the same disease．Results The total incidence of post-vaccination adverse events was 61.77/lakh in the city，with the 23-valent pneumonia vaccine manufactured by a certain company causing the highest incidence (509.19/lakh)．IndurationS and fever accounted for 45.75％ and 40.45％ of the post-vaccination adverse events and were ranked aS the first and second respectively in the list，both events together constituting 86.20％ of all the post-vaccination adverse events．Conclusion There is a significant difference in the incidence of post-vaccinatiOn adverse events between difierent bioproducts．But no significant difference was seen in the incidence between the urban areas and suburban counties．