Abstract: Objective :To study the mechanism of selective cyclooxygenase-2 (COX-2) inhibitor Nimesulide affecting growth and inhibiting metastasis of human colon cancer cells. Methods :MTT as-say and flow cytometry (FCM) were used to determine the effect of Nimesulide on the proliferation andapoptosis, as well as the cell cycle of colon cancer cells. VEGF was examined in the supernatant fluidusing ELISA. Results :Nimesulide inhibited the proliferation of colon cancer cells in a dose-and time-dependent manner and decreased the proportion of cells in the G₀/G₁ phase. They also reduced the re-lease of VEGF in a time-dependent way. Conclusions :Nimesulide can inhibit proliferation and induceapoptosis in colorectal cancer cell lines by blocking cell cycle progression, and may inhibit proliferationand metastasis of human colorectal carcinoma by down-regulation of the release of VEGF in the super-natant.