Objective:To investigate the correlation between 5-HT concentration in peripheral blood(PB)and the character of crime.Methods:We collected serum of violence criminal and nonviolence criminal at random and serum of persons without crime records or disease according to the definition of violence criminal and nonviolence criminal in law at present.The serums were divided into groups according to the sex

to do comparison on the 5-HT concentration in PB.Further the correlation between 5-HT concentration and crime character was determined through statistical analysis.Results:The 5-HT concentration in serum of violence men criminal was less than that of nonviolence men criminal and normal ones;but there was no difference between violence women criminal and nonviolence women criminal.Conclusions:There was correlation between 5-HT concentration in PB and the character of crime.