To analyze distribution characteristics of TCM constitution of patients with type 2 diabetes mellitus and to explore common constitutional types through the investigation of TCM constitution in type 2 diabetes mellitus patients.To study preliminarily the relationship between the TCM constitution and the related risk factors in order to provide scientific basis for the establishment of the pathogenesis of type 2 diabetes mellitus and the basis for clinical prevention and treatment.Methods:A total of 461 patients with type 2 diabetes mellitus who were admitted and treated in Longhua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from June 2014 to December 2015 were selected and 486 healthy people as control group.A total of 947 cases were studied.According to TCM Constitution Classification Standard of China Association of Chinese Medicine，the cases were identified and the patients were analyzed in gender，age，height，weight，BMI，history of smoking and drinking，hypertension history，cardiovascular disease history，dyslipidemia disease history and so on.Results:The distribution frequency of nine kinds of TCM constitutions in the patients with type 2 diabetes mellitus from high to low was yin-deficiency constitution，phlegm-dampness constitution，blood stasis constitution，qi-deficiency constitution，yang-deficiency constitution，dampness-heat constitution，mild constitution，qi stagnation constitution and specific constitution.The proportion of mild constitution in the patients with type 2 diabetes mellitus was lower than control group，and yin-deficiency constitution was higher (P<0.01).Logistic regression analysis screened out that yin-deficiency constitution had highest risk for the patients with type 2 diabetes mellitus (P<0.01，OR=1.887)，and mild constitution had second risk (P<0.01,OR=0.239).The difference of patients of yin-deficiency constitution with type 2 diabetes mellitus in the gender，age，weight，hypertension history，cardiovascular disease history and prevalence of dyslipidemia had statistical significance (P<0.01~0.05).Conclusion:The yin-deficiency constitution is main risk constitution and mild constitution is protection constitution for the patients with type 2 diabetes mellitus.It provides a theoretical basis for its prevention and treatment.The cardiovascular disease risk factors among the main constitutions of type 2 diabetes mellitus are different，so there may have different prognosis.We should pay attention to each index and the prevalence of related diseases to develop personalized treatment scheme.