Abstract: Objective To evaluate the effects of COX-2 selective inhibitor Celecoxib on the migration and invasion of human Osteosarcoma MG-63 cell lines，and study the anticancer mechanisms of Celecoxib. Methods The MG-63 cells were divided into five groups:4 test groups(celecoxib concentrations:25μmol/L,50μmol/L,100μmol/L and Celecoxib 50μmol/L+ PGE210μg/ L)and control group.MTT assay,scratch wound assay and Transwell chamber in vitro invasion assay were used to detect the change of proliferation,migration and invasion of MG-63.The levels of MMP-2 and MMP-9 were evaluated by enzyme-linked immunosorbent assy(ELISA). Results The proliferation of MG-63 was not inhibited significantly within 24 hours(P＞0.05）, contrarily,inhibited significantly after 48 hours（P＜0.05）.Meantime,both migration and invasion of MG-63 cells were depressed. The levels of MMP-2 and MMP-9 were downregulated significantly(P＜0.05) after 24 hours. All these effects with a dose-dependent manner, could not be reversed completely by PGE2. Conclusion The selective COX-2 inhibitor Celecoxib might inhibit the proliferation,migration and invasion of human Osteosarcoma MG-63 cell lines through downregulating the levels of MMP-2 and MMP-9, which partly was COX-2-independent.