This study aimed to investigate the mechanism by which the human lung cancer drug resistance-related gene BC006151 regulates chemosensitivity by down-regulating BC006151 expression via antisense gene transfer in H446/(C)DDP cells. A retroviral vector containing the antisense BC006151 sequence was constructed and transfected into H446/(C)DDP cells. Transfection of the empty vector served as a negative control. The two groups of transfected cells were treated with various chemotherapeutic agents, after which morphological changes in cell ultrastructure were compared by transmission electron microscopy, cell proliferation and chemosensitivity to particular chemotherapeutic agents were compared by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method, the effects of chemotherapy on cell cycle and apoptosis were compared by flow cytometry, and Bcl-2 was evaluated by immunohistochemistry and Western blot analysis. Results showed that apoptotic body-like structures were identified by transmission electron microscopy in the antisense gene-transfected cells. MTT founded that these cells exhibited a significantly lower level of proliferation than the control cells (p<0.01), together with a markedly increased sensitivity to various chemotherapeutic agents (p<0.01). Flow cytometry analysis revealed that a G1 phase arrest accounted for the reduction in proliferation in the antisense gene-transfected cells; increased apoptosis was also detected (p<0.01). Both immunohistochemistry and western blot analysis confirmed that Bcl-2 expression was significantly down-regulated in the antisense gene-transfected cells compared to controls. In a word, down-regulation of BC006151 can significantly inhibit proliferation and increase apoptosis of H446/(C)DDP cells after chemotherapy, and this gene may play an important role in the development of multidrug resistance in lung cancer.