Objective     To study the effects of oleanolic acid on proliferation and apoptosis of human hepatoma cell line Hep3B and their relationship with intracellular calcium ion concentration [Ca

2+

]

i

.     Methods     The cell morphology changes of Hep3B cells treated with 0

40

80

and 100 μg/ml oleanolic acid solutions for 24 h were observed by DAPI sta

ining and fluorescent microscopy. The proliferation of Hep3B cells treated with 11 different concentrations of oleanolic acid solutions (5-400 μg/ml) for 24 h were studied through MTT assay. The cell cycle change

cell apoptosis rate

and [Ca

2+

]

i

of Hep3B cells treated with 80

100

and 150 μg/ml oleanolic acid solutions for 24 h were measured by flow cytometry. The correlation between calcium ion fluorescence intensity and cell apoptosis rate was analyzed.     Results    Apoptosis of Hep3B cells was observed after oleanolic acid treatment. Different concentrations of oleanolic acid solutions inhibited the proliferation of Hep3B cells

and the inhibition effect was dose-dependent within 5-100 μg/ml. The IC

50

values were 86.04 μg/ml and 93.29 μg/ml at 24 h and 48 h of oleanolic acid treatment

respectively. The cell cycles of the treatment groups were arrested in G2/M phase. [Ca

2+

]

i

of the treatment groups increased significantly as compared with the control group（

P

<

0.05）. The apoptosis rate and [Ca

2+

]

i

increase were dependent on the concentration of oleanolic acid solution. Linear correlation was found between calcium ion fluorescence intensity and cell apoptosis rate（

P

<

0.05）.     Conclusion     Oleanolic acid can inhibit the proliferation of human hepatoma Hep3B cells and can induce Hep3B cell apoptosis through increasing [Ca

2+

]

i

.