Abstract: Objective To study the effects of trichloroethylene on apoptosis,c-myc and p53 expression in rat spermatogenetic cells.Methods Male SD rats were divided into 3 groups and there were 5 rats in each group.Trichloroethylene at the doses of 1 500 and 3 000 mg/kg was given to the rats by gavage.Apoptosis was measured with flow cytometry.c-myc and p53 expression in rat spermatogenetic cells were measured with RT-PCR.Results The apoptosis rate of spermatogenetic cells in rat testis were 22.11±2.29 and 25.96±1.74 at the doses of 1 500 and 3 000 mg/kg trichloroethylene,respectively,with significant differences from that of the control(5.59±1.89,P<0.01).Proliferation index of spermatogenetic cells were 15.51±0.89 and 13.91±1.02,respectively,and lower than that of control(20.78±3.52) significantly.Trichloroethylene at those doses also increased proto-oncogene c-myc and p53 expression obviously in rat testis spermatogenetic cells(P<0.01).c-myc mRNA were 0.698±0.067 and 0.837±0.062,and p53 mRNA were 0.619±0.109 and 0.761±0.094 at the doses of 1500 and 3 000mg/kg trichloroethylene,respectively.Conclusion Trichloroethylene induces apoptosis,inhibits proliferation and causes overexpression of c-myc and p53 in rat testis spermatogenetic cells.