A series of berbamine glycosides was designed, synthesized and evaluated as a new class of antitumor agents. An efficient glycosylation route was developed for berbamide derivatives. The newly synthesized glycosides were evaluated for their cytotoxic activity in vitro against a human leukemia cell line K562, a human lung adenocarcinoma cell line A549 and mouse lymphocytic leukemia cells L1210. In contrast to berbamine most of its glycosides manifested potent cytotoxic activities. The acetyl glycosyl berbamine 5a, 5d caused distinct improvement against K562, A549 and L1210. It is suggested that the acetyl D-glucose residue has affinity to these cancer cells.