Objective The study aimed to analyze the main risk factors of diabetes mellitus in different districts of Ninghai county.Method A total of 3 210 cases including 715 cases form town center,1 413 cases in the coastal area and 1 082 cases in mountain areas were investigated by multistage cluster random sampling.Risk factors of chronic diseasesurvey was developed in January 2016,Chi square tests and logistic regression were performed to compare differences.Result The survey was conducted in 277 diabetic patients,with a prevalence of 8.63%.The prevalence of diabetes was 13.99% (100/715),7.29% (103/1 413)and 7.84% (74/1 082) for town center,coastal area and mountain area.The prevalence of diabetes mellitus in town centers was higher than that in coastal and mountainous areas(x2=33.64,P<0.05).The results of multivariate Logistic regressionanalysis suggested that regional factors are the main influencing factors of diabetes mellitus.Compared with urban areas,the risk of diabetes mellitus in coastal areas(OR=0.492,95%CI0.350-0.690) and mountainous areas (OR=0.479,95%CI0.336-0.684)is lower.Familyhistory of diabetes mellitus(OR=4.405,95%CI3.022-6.420),long-term static time (OR=1.092,95%CI1.034-1.153),central obesity(OR=1.699,95%CI1.230-2.346),hypertension(OR=1.837,95%CI1.346-2.508) and dyslipidemia (OR=2.143,95%CI1.614-2.846)are risk factors for diabetes mellitus.Low age group (15-29 years old is the smallest,OR=0.032,95%CI0.008-0.136)and proper eggconsumption(minimum frequency per day,OR=0.347,95%CI0.183-0.661)were protective factors.Conclusion Regional factors are the main influencing factors of diabetes mellitus in Ninghai County.Prevention and control should be tailored to local conditions.We should make monitoring and early prevention,and carry out targeted intervention in a targeted manner.