Abstract: Objective : To study the effects of rAd-ODC/Ex3as on lung cancer cells in vitro. Methods : The infection rate of rAd-ODC/Ex3as was measured with the aid of GFP expression. Western Blot technique was used to observe the inhibition of ODC expression in the infected tumor cells. The malignant phenotype of A-549 cells was assessed by growth curve. TUNEL was used to analyze the cell apoptosis. Results : Approximate 75% of A-549 cells were infected with rAd-ODC/Ex3as when MOI reached 50. The expression of ODC was inhibited in the infected tumor cells. The rAd-ODC/Ex3as could inhibit the growth of A-549 cell and invasive ability at 20 of MOI. TUNEL proved that rAd-ODC/Ex3as can lead to cell apoptosis. Conclusion : The rAd-ODC/Ex3as could effectively inhibit the expression of ODC gene and the growth of lung cancer cell A-549 and induce the apoptosis. It may be one of the promising medicines for anti-sense gene therapy in lung cancer.