Abstract: Objective To investigate the interaction of Cadmium and Selenium to the content of monoamine transmitter in mouse.cerebral cortex.Method Kunming mice 2-3 day after birth were chosen,and received intraperitoneal injection of Cd,dosed from 0.0,0.5,1.0 mg/kg body weight,and other three groups treated with equal doses Cd as well as 0.35mg/kg body weight Se,after 45 day exposure,10 mice were picked up randomly from each group,male and female are 50% respectively.Cerebral cortex was removed after sacrifice,the content of monoamine transmitter was detected by high-performance liquid chromatography with electrochemical detection(HPLC).Results The data show that different dose of Cd has different influences on the content of monoamine transmitter in cerebral corte.Conclusion The effect of Cd varies because of Se,the mechanism is to be studied further.