Abstract: Objective To investigate the association between monoamine oxidase A(MAOA) gene polymorphism and violent behavior.Methods Polymerase chain reaction-sequence specific primer(PCR-SSP) was applied to detect rs6323 single nucleotide polymorphism loci of MAOA gene of in 91 prisoners with violent behavior(case group) and 101 normal prisoners(control group).The genotypes of MAOA were analyzed by gel electrophoresis.The distribution of genotypic and allelic frequencies in case and control groups was analyzed with SPSS13.0.Results GG genotype frequencies in the case and the control group were 50.5% and 58.4%.TT genotype frequencies in the case and the control groups were 49.5% and 41.6%.Gallelic frequencies in the case and the control group were 50.5% and 58.4%.Tallelic frequencies in the case and the control group were 49.5% and 41.6%.No significant difference was found in the frequencies of trs 6323 between the case and the control(P>0.05).Conclusion The variance of MAOA gene polymorphism is not associated with violen tbehavior.