For the purpose of improving the accordance rate with early diagnosis of osteosarcoma, we used the osteosarcoma cell line (HOS-8603) to establish 6 cell lines of anti-human osteosarcoma monoclonal antibodies (OSMAb) and sifted out 2 lines (OSMAb-H7, OSMAb-B4) through ELISA and immunofluorescent methods, which could secrete antibodies with high specificity. By antibodies prepared, purified and labeled with 125I we performed a series of experiments in NC nude mouse osteosarcoma models of soft tissue and bone tissue, and found the guiding localization showed stronger specificity. Then we chose OSMAb-B4 treated by bacterial filtration and labeled with 131I to do ?-scintigraphical localization examinations in 8 cases of bone tumor and obtained satisfactory results.