The previous studies have showed that endosulfan has adverse effects on male reproductive system and the oxidative stress induced by endosulfan is related to its toxicity.However, the molecular mechanism of endosulfan reproductive toxicity is still unknown.To investigate its mechanism of toxicity, the GC-lspg cells were exposed to 0, 6, 12 and 24μg/mL endosulfan for 24h, respectively.Results showed that endosulfan resulted in a dose-dependent reduction in cell viability and increases in LDH release, apoptosis rate, the malondialdehyde(MDA) level, the reactive oxygen species(ROS) production and DNA damage degree including the percentage of tail DNA, tail length, tail moment (TM) and Olive tail moment (OTM).Endosulfan induced the arrests of both S and G2/M phase and proliferation inhibition.The expression of PKC-α, CDK2, Cyclin E, RAF-1, MEK1/2, p-MEK1/2, ERK1/2 and p-ERK1/2 in GC-lspg cells declined remarkably after treatment with endosulfan.Endosulfan also damaged the microfilament,microtubule and cell nucleus, and blocked the mitosis process.The results suggested that endosulfan could induce the cell cycle arrest and proliferation inhibition by inhibiting the protein expression of cellular signaling pathway mediated by PKC-α because of DNA damage resulted from oxidative stress; meanwhile, endosulfan could also lead to mitotic arrest through directly damaging the cytoskeleton and cell nucleus resulted from oxidative stress; which therefore induced cytotoxicity of GC-1 spg cells.