Objective: To investigate the growth inhibitory and apoptosis-inducing effect of icariin on hepatocellular carcinoma SMMC-7721 cells. Methods: The proliferation of SMMC-7721 cells after exposure to different concentrations of icariin (0, 6.25, 12.5, 25, 50, 100, 200, 400 and 800 μg/mL) for different time periods (24, 48 and 72 h) was determined by MTT assay. The cell cycle and apoptotic changes as well as the protein expression of PCNA, Bcl-2 and Bax in SMMC-7721 cells after incubation with different concentrations of icariin for 48 h were detected by using flow cytometry and Western blot analysis, respectively Results: Compared with the control group (0 μg/mL), each concentration of icariin significantly inhibited the proliferation of SMMC-7721 cells, and this effect acted in a time- and concentration-dependent manner (all P<0.05). In a concentration-dependent manner, icariin showed the effects of G0/G1 cell cycle arrest and apoptosis induction, up-regulating PCNA and Bcl-2 expression, and down-regulating Bax expression (all P<0.05). Conclusion: Icariin has proliferation inhibitory and apoptosis-inducing effect on SMMC-7721 cells.