Abstract: Objective To investigate the growth of nasopharyngeal carcinoma cell line CNE-2 treated with a selective cyclooxygenase-2 inhibitor, Celecoxib. Methods The cell survival rate was measured by MTT assay, the cell cycle and apoptosis were analyzed using flow cytometric method (FCM), the expression of COX-2 protein in CNE cells treated with Celecoxib was detected by SP method. Results Celecoxib remarkably inhibited the growth and proliferation of CNE-2 tumor cells, which was demonstrated in a time-and dose-dependent effect. The DNA content in each phase of cell cycle has significantly changed as follows; cell numbers in G₀~G₁ fraction increased significantly (from 47.03% up to the highest percentage of 79.20%), whereas it decreased in S and G₂-_M phase of cell cycle. Apparently apoptosis was induced in CNE-2 cells by celecoxib. From the result of immunochemistry SP method it suggested that Celecoxib dramatically suppressed the expression of COX-2 in CNE-2 cells. Conclusion Celecoxib effectively inhibited the growth and proliferation of CNE-2 tumor cells which induces accumulation of tumor cells in G₀/G₁ phase. Importantly, the mechanism of antitumor effect by Celecoxib may include COX-2 dependent ways.