ccording to WHO diagnostic criteria of diabetes mellitus(DM),a survey of DM and im-paired glucose tolerance(IGT)was performed in the population of Changsha of Hunan Provincein P.R.China,in which 5124 subjects were investigated during the spring of 1995.The resultsshowed that the average rates of prevalence of DM and IGT were 3. 06%and 3. 93%,respective-ly,standardized by census 1990 in China. The rates of both DM and IGT increased with age.Noses difference in the prevalence of DM was found,but the prevalence of IGT was higher in fe-males(4.82%)than in males(3.50%).The symptomless DM patients accounted for 78.8%of newly diagnosed subjects with DM. The body mass index. the ratio of waist/hip and the meanvalue of blood pressure were significantly higher in persons with DM or IGT than in nomal con-trols. These findings indicate that the age and body weight as well as blood pressure are impor-tant factors to the prevalence of DM and IGT.