Objectives To investigate the correlation between impulsive aggression behavior and 5-hydroxytryptamine 1B receptor（ 5-HTR1B） rs6296 gene polymorphisms in both Uygur and Han patients with bipolar disorder. Methods A total of 868 patients with bipolar disorder were collected in a case-control study. There were 184 Uygur bipolar patients（ 92 males and 92 females） in the impulsive aggression group， and 326 Uygur bipolar patients（ 174 males and 152 females） in the no impulsive aggression group. There were 112 Han bipolar patients（ 50 males and 62 females） in the impulsive aggression group， and 246 Han bipolar patients （134 males and 112 females） in the no impulsive aggression group. Patients were assessed using the modified overt aggression scale（ MOAS）. The polymorphisms of rs6296 were identified by PCR direct sequencing， and the differences of 5-HTR1B rs6296 polymorphisms were analyzed. Results No significant difference in the genotype and allele frequency of rs6296 was found between the impulsive aggression group and no impulsive aggression group in Han bipolar patients（ P＞0.05）. However， significant differences in the genotype and allele frequency of rs6296 were found between the impulsive aggression group and no impulsive aggression group in Uygur bipolar patients（ P ＜0.05）. Conclusions There was no correlation between impulsive aggression behavior and 5-HTR1B rs6296 polymorphisms in Han bipolar patients. However， the impulsive aggression behavior in Uygur bipolar patients is closely related to the rs6296 genotype and allele polymorphism of 5-HTR. At the same time， allele G may increase the risk of impulsive aggression behavior in patients in Uygur bipolar group.