he proliferous effects of Xanthium serum on BEL-7402 strain cells were determined with methods of clone formation,and the apoptosis rate of cell was detected with flow cytometer.The results showed that the clones in three Xanthium serum groups(low, medium and high doses) and the 5-FU group were decreased compared to the control group,with the inhibition rates of 18.30%,49.34%, 68.12% and 53.27%,as well as apoptosis rates of 6.1%,8.2%,16.3% and 11.3%,respectively.Xanthium serum has significant toxic and inhibitory effects on BEL-7402 strain cells proliferation.