Osteosarcoma is the most common primary malignant tumor in the orthopaedic field. Recently, the management of osteosarcoma was evolved in many aspects and the improved results were reported in many articles. The purpose of this study is to evaluate the changes of clinical findings and management modalities in osteosarcoma since 1980. We reviewed 127 osteosarcomas managed from 1980 to 1992. The Enneking surgical stage was as follows; stage I 12 cases, stage II 98 cases and stage III 17 cases. They were subclassified into classic(97 cases), parosteal(12 cases), telangiectatic(5 cases), secondary(4 cases), periosteal(2 cases), gnathic(2 cases), high grade surface(1 cases) and undetermined(4 cases). The disease-free survival rate was evaluated for the patients of stage II classic osteosarcomas treated with amputation(27 cases) or limb-salvage operation(23 cases), and average follow up period of them was 49 months. In 27 cases of amputation adjuvant chemotherapy was administered in 23 cases. And in 23 patients treated with limb-salvage operation, neoadjuvant and adjuvant chemotherapy were done in 19 cases and only adjuvant chemotherapy in 2 cases. The clinical changes since 1980 were as follows: (1) The mean duration from symptom onset to diagnosis was decreased gradually from 6.5 months(1980) to 3.1 months(1992). (2) The proportion of curative surgery was increased from 40%(1980) to 87%(1992) in stage I and II. (3) The proportion of limb-salvage operation was rapidly increased upto 88% since 1985. The 5 year disease-free survival rate of stage II classic osteosarcoma was 36% with amputation and 67% with limb-salvage operation.