Abstract: To investigate the effects of sanguinarine (Sang) combined with cisplatin (Cis) in accelerating the apoptosis of bladder cancer EJ cells, CCK-8 method was used to detect the proliferation of bladder cancer EJ cells treated with different concentrations of Sang with the IC₅₀ values calculated. Annexin V FITC/PI method was used to detect cell apoptosis in the control group, Sang group, Cis group and the combination group. Flow cytometer was used to detect cell cycle arrested. Western blot was used to detect the influence of Bcl-2 expression in the control group, Sang group, Cis group and the combination group. Nude mouse subcutaneous tumor model was constructed to verify that the combination group could accelerate the apoptosis of bladder cancer EJ cells and reduce the side-effects on mice. The safety of the Sang was evaluated by HE staining of vital organs in mice. In vitro, Sang could significantly inhibit the proliferation of EJ cells. Compared with the control group, the number of apoptosis EJ cells in the combination group was significantly increased (P < 0.05), and more cells were arrested in G₂/M phase. The expression of Bcl-2 was significantly down-regulated in the combination group (P <0.001). In vivo, compared with the control group, the tumor growth was significantly slower, and a large number of apoptotic cells were inspected (P < 0.05) of the combination group. The side effects of cisplatin were reduced in the combination group. Sang has high biosafety and little side effect. Combined Sang and Cis can increase cell cycle G₂/M block, down-regulate Bcl-2 expression, promote cell apoptosis and inhibit tumor growth.