Objective:To investigate the status of depression and physiological, psychological and social factors among people with type 2 diabetes(T2DM), as well as the mediating effects of illness perception and diabetes distress on glycemic control and depression.Methods:A total of 511 patients with type 2 diabetes were recruited and investigated using general demographic questionnaire, self-rating depression scale(SDS), brief illness perception questionnaire(BIPQ) and diabetes distress scale(DDS). Body mass index (BMI) and hemoglobin a1c (HbA1c) were detected in laboratory.Results:The mean score of SDS was (57.48±9.94). The distribution of depression condition were 138(27.0%)without depression, 179(35%)with mild depression, 174(34.1%)with moderate depression and 20(3.9%)with severe depression.SDS score was significantly positively correlated with poor glycemic control ( r=0.157, P<0.01), illness perception( r=0.359, P<0.01) and four dimensions of diabetes distress( r=0.177-0.354, P<0.01). Partially mediating effect of illness perception( B=0.216, 95% CI=0.112-0.372) was found in glycemic control and depression, the proportion of effect was 25.9%.The chain mediating effect ( B=0.086, 95% CI=0.042-0.149) of illness perception and diabetes distress was also found between glycemic control and depression, whose indirect effect size was 10.3%. Conclusion:Glycemic control is significantly related with depression.Illness perception and diabetes distress are partly mediating the effect between glycemic control and depression.