Abstract: Objective :To study the the effect of selective COX-2 inhibitor Celecoxib on proliferation and apoptosis of gastric cancer cell. Methods :Investigate the effect of Celecoxib on proliferation of gastric cancer cell line SGC-7901 by MTT assay.Detect the change of apoptosis,cell cycle and the expression of COX-2,bcl-2 protein using flow cytometry analysis. Results :Celecoxib could inhibit the proliferation of SGC-7901 cell and showed a time-and dose-dependent manner.The highest survival rate of SGC-7901 cell is 48.7% and the lowest is 20.5% after 72 hour of Celecoxib action.The content of COX-2 and bcl-2 protein was decreased from 26.73±0.06 to 5.79±1.44,from 2.76±0.14 to 0.78±0.05 respectively.The decrease of them showed a dose-dependent manner.The apoptosis rate of the cell increased from 3% to 33% with the raise of Celecoxib concentration.The percentage of cell in G0/G1 phase increased to 87.29±1.34% and the percentage of cell in S and G2/M phase reduced to 8.91±0.78%, 3.80±0.55%,respectively. Conclusions :Celecoxib could inhibit the proliferation of SGC-7901 cell effectively through inducing apoptosis and influencing the distribution of cell cycle of SGC -7901 cell.The mechanism of Celecoxib induced apoptosis of SGC-7901 cell mainly through inhibit the biological activity of COX-2 and may associated with the down-regulation of bcl-2 protein.