Objective To investigate the effect of insulin resistance on outcome and social function in patients with bipolar disorder at remission stage. Methods The body mass index(BMI),the levels of fasting plasma glucose,insulin and glyeosylated hemoglobin were detected in 90 BD patients without diabetes(BD group)and 30 normal controls (NC group). Alda scale was used to assess treatment response, and Global Assessment of Functioning Scale was used to assess social function. The effect of insulin resistance on outcome and social function was analyzed. Results Patients with bipolar disorder with type 2 diabetes or insulin resistance have poor response to treatment(2.50,2.93 vs 4.77,F=5.636,P<0.01;OR=6.07& 4.78,P<0.01), more recurrences (0,0.03 vs 0.33,F=59.475,P<0.01;OR=1.59&4.82,P<0.01), and worse social function (GAF:56.90,53.23 vs 73.93,F=6.010,P<0.05). Treatment response and social function were negatively correlated with insulin resistance index (r=-0.383,-0.307,P<0.01), and social function was associated with treatment response, atypical antipsychotics, and side effects (r=0.467, -0.314,-0.407,P<0.05 or P<0.01). Conclusion Diabetes mellitus or insulin resistance may be important factor in therapeutic resistance and social function to patients with bipolar disorder.