Objective：To investigate the effect of NS-398,a selective cyclooxygenase-2 (COX-2 ) inhibitor,on the proliferation and invasion of human colon carcinoma cells in vitro,so as to determine the possibility of COX-2 as a new target for treatment of colon carcinomaMethods: The expression of COX-2 in colorectal cancer cells (CW-2,COLO-320) was detected by RT-PCR and Western blottingCOLO-320 cell proliferation was measured by MTT after treatment with NS-398Cell invasion ability was measured using migration and invasion chamber systemsWestern blotting assay was used to examine the influence of NS-398 on MMP-2 expressionResults: Our results showed that CW-2,COLO-320 cells expressed COX-2 mRNA and proteinNS-398 inhibited the proliferation of COLO-320 cells in a time- and concentration-dependent mannerInvasion test showed that NS-398 inhibited the migration and invasion of COLO-320 cellsWestern blotting revealed that NS-398 inhibited the expression of MMP-2 in COLO-320 cellsConclusion: The selective COX-2 inhibitor NS-398 can inhibit COLO-320 cell proliferation and invasion,indicating COX-2 may serve as a new target for colon carcinoma treatment