Objective: Despite advances in multimodal therapy, osteosarcoma (OS) still imposes big challenge due to its high rate of metastasis. The previousstudies reported that aberrant glycosylation in the cells mediates the invasion of several cancers including OS. However, its mechanism, particularlyN-glycosylation in OS progression, is still poorly understood. Thus, this study aims to investigate the effect of glycosylation inhibitions toward OS cellsinvasiveness.Materials and Methods: Both 1-deoxynojirimycin (DNJ) and 1-deoxymannojirimycin (1-DMJ) were used to inhibit the activities ofalpha-glucosidase-I/II and alpha-1,2-mannosidase, respectively. Invasion assay and real-time polymerase chain reaction (PCR) (quantitative PCR[qPCR]) analysis of extracellular matrix-related genes were performed at post 24 h of treatment with the inhibitors, 0.5 mM 1-DNJ and 0.5 mM 1-DMJ,respectively, on the OS cell line, MG-63.Results: Results showed that the inhibition of N-glycosylation with 1-DNJ decreases the invasion rate of MG-63 cells while the inhibition ofN-glycosylation by 1-DMJ caused the invasion rate of MG-63 cells to increase. qPCR analysis showed downregulated expression of matrixmetalloproteinase (MMP2) gene in both types of treatments while the expression of its inhibitor, tissue inhibitor of metalloproteinase (TIMP2) wasupregulated in both types of treatments. In this study, MMP9 genes were not detected in both samples; however, the expression of its inhibitor, TIMP1was downregulated in MG-63 cells treated with 1-DNJ but upregulated in 1-DMJ treated cells.Conclusion: It is concluded that 1-DNJ reduced the invasion rate in MG-63 cells through downregulation of MMP2 gene which subsequently reduceddegradation of collagen type IV. However, the contrasting effect showed by 1-DMJ requires further investigation to elucidate its underlying mechanism.