Abstract: Objective :To study the effect and mechanism of valdecoxib, a selective COX-2in-hibitor, on human esophageal Eca109 cell line. Methods :MTT assay and flow cytometry were used to observe the effect of valdecoxib on proliferation, apoptosis and the cell cycle distribution of Eca109 cells. The expression of p-p38, c-fos or c-jun protein was detected by flow cytometry and immunocytochemical staining. Results :Valdecoxib in 25400 (mo1.Lsignificantly inhibited the proliferation of Eca109 cell line in a time-and dose Iependent fashion, the inhibition rate of proliferation was 23.09 85.95% after 72h, and the rate of apoptosis was increased from (2.38±0.42)% to (2.95±o.8s)%-(48.46±0.73)%, 50400(mo1.L-1 valdecoxib also decreased the proliferation index and the proportion of cells in the S phase, increased the proportion of cells in the Go/G, phase, but had no effect on the proportion of cells in the GZ/M phase. Immunoc ytochemically, the positive stainings for p-p38, c-fos and c-jun were almost observed in nucleus of the Eca109 cells. Compared with those in Eca109 cells cultured in the medium with solvent, the stainings were strengthened for p-p38, c-fos and c-jun in the Eca109 cells exposed to valdecoxib in a dose lependent in 72h. Conclusions :Valdecoxib inhibits the growth of human esophageal Eca109 cell line by inducing apoptosis and cell cycle arrest. The mechanism of inducing apoptosis is partly realized by activating the p-p38/c-fos, c-jun.