To explore type 2 diabetes prevalence and its risk factors among migrants and nonmigrants aged 35 years and older in Three Gorge Dam area in Yichang City of Hubei province, China. A sample of 9865 rural residents (including 1949 Three Gorge Dam migrants and 7916 nonmigrants) aged 35 years old and over was selected from September to December in 2007 by the method of multi-stage cluster random sampling in Yiling district, Yichang City of Hubei province. The study subjects were assessed by interview, examination, and blood samples. Information on demographics, migrant information, lifestyle, history of diabetes and hypertension was obtained by a questionnaire interview. An overnight fasting blood specimen was collected to measure serum glucose, total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C) and low density lipoprotein-cholesterol (LDL-C). Height, weight, waist circumference, hip circumference and blood pressure were measured. Oral glucose tolerance test (OGTT) was carried out for t