Objective:To investigate the proliferation effect and its pathway of activin A on Ovarian epithelial cancer cells line OVCAR-3.Methods:OVCAR-3 cells were cultured in vitro and the membrane receptor ActR Ⅱ was detected by immunohistochemicai method.The OVCAR-3 cells were cultured with 10 ng/ml activin A for 7 d to observe the effects.Activin A at 5,10,15 and 20 ng/ml was used separately to treat the OVCAR-3 cancer cells for 24,48 and 72 h in order to draw the growth proliferation rate curve measured by MTT method.The expression of protein bcl-2 was detected by west-blot.When OVCAR-3 cells were treated with 10 ng/ml activin A and 5 μg/ml DDP for 24,48 and 72 h,cell apoptosis could be detected by electron microscopy and flow cytometry(FCM).Results:Positive expression of ActR Ⅱ was detected.We also found that the proliferation of OVCAR-3 reached to the climax on the 5th day of culture.The experiments showed that the cells treated with activin A increased quickly and grew faster than those in control group.Moreover,OVCAR-3 cells treated with activin A for 48 h proliferated significantly greater than those treated for 24 h or 72 h(P＜0.01).bcl-2 protein expression increased expression in activin A treated group than in control group(P＜0.05).Conclusion:Activin A could increase the proliferation of OVCAR-3 cells which may be through bcl-2 anti-apoptosis pathway.