OBJECTIVE To study the cytotoxicity of Lidamycin (LDM) and its induction of apoptosis in Raji and Daudi cells of B-cell lymphoma, and the inhibition of growth of the lymphoma Raji xenograft in nude mice.METHODS MTT assay was used to observe the inhibition by LDM on the proliferation of the Raji and Daudi cells. Annexin V-FITC/PI double-stain, in combination with flow cytometry (FCM), was used to determine the induction of apoptosis by LDM in Raji cells. The B-cell lymphoma Raji xenograft model in nude mice was set up to detect the in vivo antitumor activity of LDM.RESULTS LDM markedly inhibited the proliferation of the Raji and Daudi cells in vitro, with IC50 values of 7.13×10-11 mol/L and 2.91×10-10 mol/L, respectively. The apoptotic rates of Raji cells were respectively 77.98% and 67.63% at 0.5 nmol/L and 0.25 nmol/L of LDM, indicating an obvious induction of apoptosis in Raji cells. LDM inhibited the formation and growth of human B-cell lymphoma Raji xenograft in nude mice. The inhibition rates of tumor growth were respectively 74.9% and 65.2% in LDM at dosage group of 0.05 mg/kg and 0.025 mg/kg, suggesting an apparent prolongation of survival time in the nude mouse bearing lymphoma.CONCLUSION LDM can effectively induce apoptosis of the B-cell lymphoma cells and inhibit the xenograft growth in nude mice.