Abstract: Objective To investigate the effects of cyclooxygenase-2(COX-2) regulating E-cadherin expression on migration capability of gastric carcinoma cell line SGC-7901. Methods After SGC-7901 cell line treated by Celecoxib and PGE2 in vitro, real-time quantitative PCR was used to detect the changes of mRNA levels of COX-2 and E-cadherin. The combination of immunofluorescence and Confocal laser scanning microscopy was used to analyze the protein level of E-cadherin. Transwell was used to detect the change of cell migration. Results COX-2 mRNA expression was inhibited by Celecxib, but E-cadherin mRNA expression level was increased signifi cantly with decreased COX-2 expression, in a dose- and timedependent manner(P＜0.01).On the contrary, E-cadherin mRNA expression level was decreased in a timeand dose-dependent manner after PGE2 treatment(P＜0.05 or P＜0.01). After SGC-7901 cell line were treated with Celecxib (30 μmol/L) for 24,36,48 h, E-cadherin protein level was increased significantly(P＜0.05), while E-cadherin protein expression was signifi cantly decreased after PGE2 treatment(1 μmol/L) for 24 and 48 h (P＜0.05).The cell numbers through Transwell with Celecoxib treatment was less than that of no-treatment group(P＜0.01).While, the cell numbers through Transwell with PGE2 treatment was more than that of notreatment group (P＜0.05). Conclusion Celecoxib, selective COX-2 inhibitor, may upregulate E-cadherin expression and inhibit the invasive potential of human gastric carcinoma by suppressing COX-2 expression. PGE2 may downregulate E-cadherin expression and promote the migration of SGC-7901 in vitro.