Objective To study the effect of dibutyltin dilaurate(DBTD) on reproductive system of male rats.Methods 28 healthy male rats were divided into 4 groups,7 each.The rats were administrated orally with DBTD at the dose of 0,5,10 and 20 mg/kg,respectively,and killed after 5 weeks for measurement of ACP,LDH,NO,NOS and tin content in testis tissue.Results There was no difference in different dose groups of tin content in testis tissue compared with the control group,but the activity of LDH,NO in dose groups was different from control group.At the same time,the content of NOS in 10,20 mg/kg groups and the activity of ACP in 20 mg/kg group were also different from the control group.Conclusion The study shows that DBTD has testis toxicity,and it can disturb the activity of enzyme in testis tissue.