Cyclin L2 is a novel member of the cyclin family, recently implicated in the regulation of cell cycle progressionand/or transcriptional regulation. The present study was undertaken to investigate the effects of overexpressionon tumor cell growth and chemosensitivity in human gastric cells in vitro. Cyclin L2 was transfected into humangastric cancer cell line BCG823 and expressed with a mammalian expression vector pcDNA3.1. The effectsand mechanisms of cyclin L2 on cell growth, cell cycling and apoptosis were studied. Compared to controlvectors, overexpression of cyclin L2 inhibited the growth of BCG823 cells and enhance their chemosensitivity tofluorouracil, docetaxel and cisplatin. The anti-proliferative effects of cyclin L2 could be due to G0/G1 arrest andapoptosis. Cyclin L2 induced G0/G1 arrest and apoptosis involved upregulation of caspase-3 and down regulationBcl-2 and survivin. The results indicated that overexpression of cyclin L2 protein may promote efficient growthinhibition and enhance chemosensitivity to chemotherapeutic agents in human gastric cancer cells by inducingG0/G1 cell cycle arrest and apoptosis.