The toxicity of dauricine on daudi cell of B cell lymphoma was investigated by atomic force microscopy,CCK-8 assay and flow cytometer method.The results showed that dauricine could suppress the proliferation of daudi cells.By CCK-8 assay,it was found that cell viability was related with the reaction time and drug concentration.When 10-50 μmol/L dauricine was incubated with daudi cells for 24 h and 48 h,respectively,the cell viability declined from (89.8±4.3)% to (11.2±3.2)% and (68.9±2.6)% to (2.5±0.5)%,respectively.In addition,daudi cells were cultured with different concentrations of dauricine for 24 h,the result revealed that the apoptosis rate increased from 5.2% to 28.2% (60 μmol/L).AFM data showed that control cells were round and the surface was smooth.After treated with dauricine,daudi cell collapsed, the ultrastructure revealed that cell surface was rough and full of bumps and holes.Furthermore,daudi cells were treated with different concentrations of dauricine,the mitochondrial membrane potential of cell decreased with the increase of the dauricine concentration.Dauricine significantly inhibited the growth and proliferation of daudi cells.