Six hundred and fifty one cases of bone tumors diagnosed and operated at Department of Orthopedic Surgery, Seoul National University Hospital, from Jan., 1969 to Apr., 1989. were reviewed and analyzed with respect to the types of tumor, the age and sex distribution of the patients, the location of the lesions and the advances of diagnosis and treatment. 378 benign and 273 malignant bone tumors were identified. Osteochondroma(113 cases, 17.4%) was the most common bone tumor, followed by osteosarcoma(72 cases, 11.1%) and giant cell tumor(50 cases, 7.7%) Second decade was the most common age of bone tumors(216 cases, 33.2%) and male(379 cases, 58%) was more common than female. Femur(222 cases) was the most common site of bone tumors, followed by tibia and vertebra. For simple bone cyst, steroid injection was widely used recently. It was a simple and safe procedure and its results were similar to those of curettage and bone graft. Limb salvage operations were performed for malignant bone tumors increasingly. Neoadjuvant chemotyeraphy and limb salvsge operation using tumor prosthesis were performed in 5 patients of osteosarcoma and their results are so far promising. Of 7 cases of chondrosarcoma, the limb was salvaged by resection arthrodesis or resection arthroplasty. 7 cases of malignant fibrous histiocytoma were treated by radical ablative surgery and/or chemotherapy and radiation, but local recurrence or pulmonary metastasis were detected in all of them. So it was thought to be highly malignant bone tumors.