Abstract: Objective: To construct an animal model of pIRES-Rb94transfection of the A549 adenocarcinoma cells to investigate the inhibitory action and effect on the expression of SphK in a mouse xenograft model. Methods:Cell suspen-sions at 5 × 10 6/0.1mL were subcutaneously injected into flanks of every nude mouse. Then the inoculated mice were divid-ed into4 groups as follows: with PBS; with lipofectamine; with pIRES empty vector; and with pIRES-Rb 94. The inhibitory rate was observed and the expression of the Rb 94gene was detected by Western blot. Then its effect on SphK expression was determined by RT-PCR and immunofluorescence. Results: The growth of tumor graft was obviously inhibited in the treatment group. The inhibitory ratio of the transplanted tumor was 51.99% in the pIRES-Rb94group, higher than that in the control group ( 0), lipofectamine group (7.86% ) and pIRES group (11.78% ), with significant differences between pIRES-Rb94group and the other three groups (P<0.01). The expression of SphK 1 was down-regulated and the expression of SphK 2 was up-regulated. Conclusion:Mouse xenograft model of lung adenocarcinoma was successfully constructed us-ing eukaryotic expression plasmid containing pIRES-Rb 94gene. Rb94can effectively inhibit the growth of lung adenocarci -noma and the expression of SphK1 but can enhance SphK2 expression.