Objective To study the effect of liensinine on the proliferation of humanbladder cancer T24 cells.Methods T24 cells were treated with different concentrations of liensinine.Its influence on the cell proliferation was detected by the CCK-8 exper-iment and the clonogenic experiment.After staining of T24 cells,the influence of liensinine on the cell cycle was examined by the flow cytometry.The mRNA change of p2 1 gene was determined by real-time quantitative PCR.Results Compared with the con-trol,liensinine significantly inhibited the proliferation of T24 cells in different doses groups(1.562 5,3.125 0,6.250 0,12.500 0, 25.000 0μg/mL),the differences had statistical significance and showed the dose-dependence;the cell cycledetection results re-vealed that liensinine arrested the T24 cells at the S phase;the real-time quantitative PCRdetection results showed that liensinine increased mRNA of p21 gene in T24 cells.Conclusion Liensinine inhibits the proliferation of T24 bladder cancercells and arrests the T24 cells at S phase,its mechanism may be related with the upregulation of p21 expression.