Abstract: Objective To define the biological effects of human ovarian carcinoma SKOV3 cells line(SKOV3 cells)in vitro after treatment with polyphyllins I(P-I).Methods The proliferation-inhibiting effect and cycle of SKOV3 cells which were treated with different concentrations of P-I for different times in vitro were detected by CCK-8 colorimetric and flow cytometry respectively,and the cell apoptosis was examined by Hoechst 33258 fluorescent staining and Annexin-IP double staining.Results In a certain range of P-I concentration,the proliferation and growth of SKOV3 cells in vitro were inhibited which showed a clearly dose-effect relationship,and the difference existed statistically significance when compared with the control group(P＜0.01);P-I had high sensitivity on G₀/G₁ phase of SKOV3 cells cycle;and the results showed that P-I induced apoptosis in SKOV3 cells.Conclusion P-I may interfere DNA synthesis,inhibit proliferation and induce apoptosis in human ovarian cancer cells,thus playing a role in anti-ovarian cancer.