〔Abstract〕 Objective To study the expression of QSOX1 in osteosarcoma tissues and cells and its role in proliferation, migration and invasion. Methods Western blot and immunohistochemistry were used to verify the expression of QSOX1 in osteosarcoma tissues and cells, and the cell line MG63 with the highest expression was selected.Slow virus knocked down and selected stable strains shQSOX1 group and shCtrl group.Western blot was used to detect the expression level of QSOX1 protein in MG63 after transfection.CCK-8 assay was used to detect the level of cell proliferation.Scratch test verified the level of cell migration.Transwell test was used to detect the invasion ability of cells; Western blot was used to detect the mRNA expression level of NF-κB signal pathway in shCtrl group and shQSOX1 group. Results Western blot and immunohistochemistry showed that QSOX1 was low expressed in human osteoblast line hFOB1.19 and adjacent tissues, but high expressed in osteosarcoma tissue and osteosarcoma cells(P<0.001).CCK-8 experiment showed that the proliferation ability of shQSOX1 group was inhibited compared with shCtrl group(P<0.05);In the scratch test, the migration ability of shQSOX1 group decreased(P<0.001);Transwell proved that the invasive ability of shQSOX1 group was affected(P<0.001);NF-κB was highly expressed in shCtrl group and low expressed in shQSOX1 group(P<0.001). Conclusion QSOX1 is highly expressed in osteosarcoma.Knockout of QSOX1 gene can inhibit the proliferation, migration and invasion of osteosarcoma.Knockout of QSOX1 makes NF-κB signal pathway is deactivated.