OBJECTIVE： To study the inhibitory effects of emodin on the proliferation of human hepatocellular carcinoma SMMC7721 cells. METHODS： SMMC7721 cells were treated with 0 （negative control）， 25， 37.5， 50， 62.5， 75， 87.5， 100 μmol/L emodin solution and 100 μmol/L 5-FU for 24 h， 48 h， 72 h. The optical density value of cells was detected， and inhibition rate was calculated. SMMC7721 cells were treated with 0 （negative control）， 25， 50， 75 μmol/L emodin solution and 100 μmol/L 5-FU for 48 h， and cell apoptosis rate， cell cycle and the expression of Bax and Bcl-2 gene were detected. RESULTS： Compared with negative control， the rate of cell proliferation inhibition increased after treated with 25， 37.5， 50， 62.5， 75， 87.5， 100 μmol/L emodin and 100 μmol/L 5-FU， which was positively associated with the concentration and duration. Compared with negative control， the rate of cell apoptosis increased after treated with 25， 50， 75 μmol/L emodin solution and 100 μmol/L 5-FU； the expression of Bax increased and that of Bcl-2 dereased； 50， 75 μmol/L emodin solution and 100 μmol/L 5-FU could arrested cells at G0/G1 phase （P＜0.05 or P＜0.01）. CONCLUSIONS： Emodin can inhibit the proliferation of SMMC7721， promote cell apoptosis and inhibit cell growth.