Abstract: OBJECTIVE To investigate the mechanism of Chuanxiong polysaccharide inhibiting proliferation and inducing apoptosis of human hepatoma cell HepG2. METHODS Human hepatoma cell line HepG2 were cultured in vitro， added with different concentrations of Chuanxiong polysaccharide. HepG2 cell activity was detected in MTT method; cell morphology was observed and HepG2 cell cycle was detected in flow cytometry. RESULTS HepG2 cell viability reduced with increasing concentration and the inhibitory effect showed a significant dose-dependent (P<0.05); compared with blank group， after 48h， percentage of cells in drug-administered group in G1 phase significantly increased (P<0.01) while the percentage of cells in S phase significantly reduced(P<0.01). CONCLUSION Chuanxiong polysaccharide can significantly inhibit human hepatoma HepG2 cells in vitro and inducing apoptosis by arresting tumor cells in G1 phase.