Abstract： Objective To explore the effect and mechanism of p53 in mitochondrial dysfunction and apoptosis of immature Sertoli cell.Methods The Sertoli cells were harvested from 14-day-old Sprague-Dawley rats' testes.The experimental group received acrolein,a major toxicant metabolite of cyclophosphamide (CP) while the control group had phosphate buffered solution.At 10,30 and 60 min,the cells were stained with fluorescent antibody for detecting the migration of p53.At 1,3 and 12 h,the expressions of p53 and Bax were detected by Western blot and mitochondrial membrane potential and cell apoptosis by flow cytometry.Results As compared with controls,there were a few p53 in mitochondria at 10 min.However,p53 protein increased significantly at 30 min and then stabilized up to 1 i.In experimental group,the expressions of p53 and Bax increased and mitochondrial membrane potentials were (87.43 ± 0.76)％,(72.0 ± 1.73)％ and (51.53 ± 1.93)％ respectively.All decreased significantly as compared with control group (98.07 ± 0.67) ％ and the rates of cellular apoptosis were (3.25 ± 0.18) ％,(8.74 ± 0.64) ％ and (36.87 ± 0.61) ％ respectively.All increased significantly as compared with control group (0.43 ± 0.13)％.Conclusions Acrolein may induce an apoptosis of Sertoli cells through activating p53 signaling network and damaging mitochondrial functions.It will provide new conceptual and experimental rationales for further elucidating the reproductive toxicity mechanism of CP and designing a more effective protective strategy.