Objective To compare various risk factors of bipolar disorders with and without suicidal behavior. Methods A total of 5452 inpatients were divided into 2 groups; with (n=1739)and without (n=3713) suicidal behavior within 1 week. Socio-demographic and clinical data were compared between two groups. Multiple logistic regression models were used to assess risk factors of bipolar disorders with suicidal behavior. Results Compared to without suicidal behavior group, the suicidal behavior group had significantly higher rate of the following characteristics:older age [34.8±13.6 vs. 33.3±12.8, t=-3.46, P<0.01], female (58.3％vs. 52.7％,χ2=14.83, P<0.01), history of mental trauma (10.6％vs.7.8％,χ2=10.72, P<0.01), history of suicide (4.1％vs. 0.1％,χ2=140.11, P<0.01), family history of suicide (6.7％vs. 3.9％,χ2=20.22, P<0.01), family history of mental illness (33.8％vs. 29.6％,χ2=9.33, P<0.01) and history of suicide (4.1％ vs. 0.1％, χ2=140.11, P<0.01). Logistic regression analysis showed that female (OR: 1.192, 95％CI:1.043-1.363), older age (OR: 1.008, 95％CI: 1.003-1.013), history of mental trauma (OR: 1.355, 95％CI:1.083-1.696), history of suicide (OR:39.139, 95％CI:12.230-125.256) and family history of suicide (OR:1.648, 95％CI: 1.223-2.221) were significantly correlated with suicidal behavior in bipolar disorders. Conclusions The study indicates that female, older age, history of mental trauma, history of suicide and family history of suicide may be the key independent risk factors to suicidal behavior in bipolar disorders.