Objective To determine the prevalence of diabetes mellitus and related risk factors among residents in the urban and rural area of Chengdu.Methods A cluster sampling was used to establish a study population of inhabitants aged 30 to 70.Totally,1 847 participants were enrolled in this study.Questionnaire including general information and dietary information in the past year was used to collect related data.Height,body weight and oral glucose tolerance test (OGTT) were measured.Factor analysis was used to analyze the dietary pattern while multivariate unconditional logistic regression used for risk factors in total population,urban and rural residents,respectively.Results The population standardized prevalence rates of diabetes in the overall,urban and rural residents were 20.2％,28.7％,11.1％,respectively.Among total population,middle-aged (OR=2.337,95％CI:1.305-4.185) and the elderly (OR=5.990,95％ CI:3.389-10.586) residents had higher diabetes risk than the younger ones.Administrators (OR=1.434,95％ CI:1.000-2.057) and ordinary clerks (OR=2.870,95％ CI:1.653-4.980) were more vulnerable to diabetes than peasants.Similarly,middle-aged (OR=2.973,95％ CI:1.101-8.031) and elderly (OR=5.972,95％ CI:2.267-15.730) turned out to be more predisposed than young people in the urban area.Compared with peasants,ordinary clerks (OR=2.196,95％CI:1.213-3.975) seemed to be more liable to diabetes.In the mral areas,dietary pattern with higher energy and protein (OR=1.404,95％ CI:1.113-1.772) could be subject to diabetes.Conclusion The prevalence of diabetes in Chengdu was relatively high.Age,career and dietary pattern are mainly risk factors.The factors in different districts are vaious.Intervention on nutrition should be different,area-wise.