Abstract: ObjectiveTo observe the expression of exogenous p53 gene in gastric cancer cells and its effects on the growth of tumor cells; and to investigate the effects of adenovirusmediated p53 gene on chemosensitivity of human gastric cell and the value of gene therapy combined with chemotherapy. MethodsToinvestigate the effects of recombinant adenovirus-p53 (rAd-p53) and oxaliplatin(OXA) alone and combined on the gastric cancer cell line SGC-7901 for different times,CCK-8 assay was used to examine the suppressive rate of cell growth dealt; p53 protein expression was detected by immunohistochemistry assay; and protein caspase-3 expression in cell was induced by different drugs alone and in combination by flow cytometry. ResultWhen rAd-p53 and OXA was alone used to treat the gastric cancer cell line SGC-7901, with an increase in drug concentration and treated time, the cell growth inhibition rate gradually increased; when rAd-p53 and OXA was combined to treat the gastric cancer cell line SGC-7901 for 48 h, the cell growth inhibition rate gradually increased at the lowest concentration. When rAd-p53 (5×107，5×108，5×109vp/ml) and OXA (6.25μg/ml) was combined to treat the gastric cancer cell line SGC-7901 for 48h, compared with the control group, the content of caspase-3 protein in gastric cancer cell gradually increased, but p53 protein expression didn't increase. ConclusionThe proliferation of SGC-7901 could be inhibited by rAd-p53 OXA alone, but when rAd-p53 was combined with OXA, the proliferation of cells was higher than that used alone. The combination of rAd-p53 and OXA induced cell apoptosis through mitochondrial pathway to activate downstream of caspase-3.