AIM:To study the effect and the molecular mechanism of CDX 2 over-expression on the prolifera-tion, growth and cell cycle of human gastric cancer cell line SGC-7901.METHODS:The SGC-7901 cells in LV-CDX2-GFP group were transfected with the recombinant lentivirus vector LV-CDX2-GFP, the cells in LV-GFP group were trans-fected with the negative control lentiviral vector for the negative control , and the cells in blank control group were without any treatment.The cell proliferation was detected by CCK-8 assay.The cell cycle distribution was analyzed by flow cytome-try.The expression of CDX2, Bax, Bcl-2, cyclin D1 and survivin was determined by semi-quantitative RT-PCR and Wes-tern blotting .RESULTS:Compared with LV-GFP group and blank control group , the proliferation activity of the SGC-7901 cells was significantly lower (P<0.05), the G0/G1 phase proportion increased (P<0.05), the mRNA and protein levels of Bcl-2, cyclin D1 and survivin were reduced (P<0.05), and the mRNA and protein levels of Bax were up-regula-ted (P<0.05) in LV-CDX2-GFP group.No statistically significant difference of the above indexes was observed (P>0.05) between LV-GFP group and blank control group .CONCLUSION:Over-expression of CDX2 mediated by lentivirus inhibits the proliferation and growth of human gastric cancer SGC-7901 cells and arrestes the cell cycle at G 0/G1 phase, which may be related to down-regulation of Bcl-2, cyclin D1 and survivin and up-regulation of Bax .