Abstract: Objective To find out the fever prevalence rate in each resident point and to assess the sensitivity of health facility-based typhoid fever surveillance system by applying geographic information system(GIS)technology.Methods Census data,disease surveillance data and resident global position system data were collected,and relevant GIS databases were set up and population-based fever disease surveillance system was established.All febrile cases were identified by patient' ID and address ID.A resident point case-population rate distribution GIS map was produced.Results 3 776 resident GPS points in study area were collected.In 2004,the febrile case-population rate was 1.11‰.Febrile cases accounted for 16.3% of total outpatients,and the febrile patients came from study accounted for 83.5% of total febrile outpatients.In three types of health facility,the number of outpatients in private clinics sector was the most,but the ratio of febrile outpatient to total outpatient in private clinics sector was lowest(12.6%).95% febrile outpatients' address-IDs was matched.According to the GIS map of febrile case-population rate,the highest rate of an resident point reached 17.81‰,while the lowest one was 0;More resident points with a low rate located in rural area,especially in northwest of rural area.Conclusion GIS provides a resource for rapid mapping on febrile cases distribution and the fever prevalence can be displayd visually,detailed and precisely;the weak points in surveillance system can be detected quickly and straightly and can detect or extrapolate where the problems are in the surveillance system.