Abstract： Objective To investigate the prevalence rate of depression in Chinese diabetic population and the relationship between diabetes mellitus (DM) and depression. Methods 611 cases with diabetes mellitus and 429 cases with different somatic diseases were interviewed and analyzed by Hamilton Depression Scale (HAMD). Results (1)The prevalence rates of depression in diabetes mellitus and different somatic diseases were 28.6% in DM, 9.8% in EHT (E), 9.4% in hyperthyroidism (T), 7.8% in COPD (C), and 11.5% in iron deficiency anemia. (2) Among all the subjects, the prevalence rate of depression in diabetic subjects was higher than other somatic diseases ( P <0.01). (3) Depression was found to be correlated with five factors in diabetic patients, which were woman, BMI>25, higher education level, HbA1c>8%, diabetic complications. Conclusion The prevalence rate of depression in diabetic patients is higher than other somatic diseases; depression plays an important role in the development and prognosis of DM.