Abstract: Objective To study the apoptosis of human hepatocarcinoma cells induced by genistein and its mechanism. Methods Human hepatocarcinoma SMMC-7721 cells cultured in vitro were treated with genistein. MTT test was used to examine the proliferation inhibitory rate, The morphology of apoptotic cells was observed by microscopy. DNA fragmentation was examined by gel electrophoresis. The expressions of apoptotic gene of P53、SURVIVIN and CASPASE-3 were examined by immunohistochemstry method. Results Genistein could inhibit the proliferation of human hepatoma cells in dose and time-dependent manner, The inhibitory rates were 9.86%、19.13% and 25.64% differently in 5,10 and 20μg /mL for 48h. It also could induce the apoptosis of SMMC-7721 cells, The DNA of cells presented "ladder" break. The expression of apoptosis related protein SURVIVIN was down regulated, the expressions of P53 and CASPASE-3 were up regulated. Conclusions Genistein can induce the apoptosis of SMMC-7721 cells. One of the molecular mechanisms of genistein might decrease apoptosis related protein expression of SURVIVIN and increase the expressions of P53 and CASPASE-3.