Objective:To study the role and significance of phosphatase and tensin homolog deleted on chromosome ten(PTEN)protein for the occurrence and development of endometriosis (EMs)in vitro experiments. Methods:Lentiviral vector was used to overexpress PTEN and silence PTEN expression in human primary endometrial cells; flow cytometry was used to detect the changes in cell cycle and apoptosis in the different PTEN expression groups after lentivirus infection. Results:Cell cycle analysis showed that after transfection of overexpressed lentivirus of PTEN gene,the proportion of G0/G1 phase in human primary endometrial cells was increased,compared with the control group(P <0.05). The proportion of G2/M phase was gradually decreased,and cell cycle was arrested in G0/G1 phase; In the blank group,the overexpressed PTEN group,and the siPTEN group,cell apoptosis rates were(11.70 ± 0.03)%,(15.80 ± 0.14)%,and(5.33 ± 0.08)%,respectively. Conclusion:Overexpression of PTEN could significantly increase apoptosis rate and inhibit cell cycle of human primary endometrial cells. PTEN has a certain inhibiting effect on the occurrence and development of endometriosis.