Objective:To investigate the proliferation inhibition and apoptosis in human hepatic cancer cell strain HepG2 by ilexgenin A and its mechanism.Method:HepG2 were treated by iexgenin A with different concentration and time.MTT assay

around totally orange（AO） fluorescence staining method

flow cytometry（FCM）

SP method of immunocytechemistry were used to determine the inhibiting effect on HepG2 cells

the cell cycle and apoptosis morphological changes and the expressions of Bcl-2

Bax.Result:Ilexgenin A inhibited the proliferation of HepG2 cells in dosage and time dependent manner.After HepG2 cells were treated by ilexgenin A for 24 hour

ilexgenin A induced a G1 cell cycle arrest and reduced the cell population in S phase and the apoptosis rate were 7.89%

8.37%

9.93%

respectively.With the increasing of the medicine density

the expression of Bcl-2 was down-regulated

while the expression of Bax up-regulated in the apoptosis.Conclusion:Ilexgenin A can inhibit proliferation of the HepG2 cells and induced a G1 cell cycle arrest and reduced the cell population in S phase.It also can induce apoptosis of human prostatic carcinoma through down-regulating the expressions of Bcl-2

up-regulating the expression of Bax.