OBJECTIVE To elucidate the effects of atrazine( ATZ) on apoptosis in cultured rat Sertoli cells. METHODS The Sertoli cells isolated from male SD rats( 18-21day) were used to set up Sertoli cells primary culture model in vitro, and these cells were treated with 0, 10, 50, 100 and 200 μmol / L ATZ for 24 h. Cell viability was assessed by MTT assay, and the vimentin expression of Sertoli cells was analyzed by immunofluorescence assay, and apoptosis were evaluated by flow cytometry. Real timePCR was used to analyze the mRNA levels of Fas L, caspase-3 and caspase-8, and the protein contents of Fas L, caspase-3 and caspase-8 were determined by ELISA. RESULTS The viability of Sertoli cells of 50, 100 and 200 μmol / L ATZ groups were 82. 47%, 75. 23% and 53. 76%. Compared with the control group, the viability of Sertoli cells decreased by 17. 53%( P < 0. 05), 24. 77%( P < 0. 05) and 46. 24%( P < 0. 01), respectively. The apoptosis rates of Sertoli cell of 50, 100 and 200 μmol / L ATZ groups were 8. 53%, 13. 07% and 14. 45%. Compared with the control group, the apoptosisrates of Sertoli cells were increased by 86. 86%( P < 0. 01), 186. 13%( P < 0. 01), 216. 06%( P < 0. 01), respectively. the mRNA and protein expressions of Fas L, caspase-3 and caspase-8 were significantly increased at 50, 100 and 200 μmol / L ATZ groups( P < 0. 05, P < 0. 01). The Vimentin expression of Sertoli cells was inhibited in treated groups. CONCLUSIONS ATZ can affect the viability of Sertoli cells, and induce apoptosis of Sertoli cells through a Fas L dependent pathway.