Objective To investigate the prevalence of depression and its risk factors in type 2 diabetes mellitus.Methods Beck Depression Inventory (BDI) was used to evaluate depression in 2 966 type 2 diabetes mellitus patients [ male 1 463,female 1 503,age ( 56.4 ± 11.2 ) years,diabetes duration ( 6.3 ± 5.7 ) years ].Depression criteria:≤4 points,no depression group; 5-13 points,mild depression group; 14-20 points,moderate depression group; 21 points or higher,severe depression group.Meanwhile,the demographic and metabolic data and diabetes-related health behaviors were also investigated.The risk factors associated with depression were screened by logistic regression.Results 51％ patients had depression,including 38％ with mild,8％ with moderate,and 5％ with severe depression.Compared with no depression group,depression was correlated with female sex,low-annual income,diabetes education,diabetes treatment,with insulin and peripheral neuropathy( P＜0.01 ).More smoking and younger age were found in severe depression( P＜0.05 ).Partial correlation analysis showed that depression in type 2 diabetes mellitus was positively correlated with female sex,diabetes education,and peripheral neuropathy ; and negatively correlated with age (P＜0.05).Conditional logistic regression equation showed that gender( OR =1.37 ),age ( 20-40 years,OR =1.52 ),diabetes education ( OR =1.51 ),and peripheral neuropathy ( OR =1.87 ) were risk factors for depression.Conclusion Depression is common in type 2 diabetes mellitus.More attention should be paid to screening depression in clinical practice.