The clinical features of 141 patients with osteosarcoma were analysed and conventional radiographs of 92patients out of 141 patients were reivewed retrospectively in order to assess the distribution of the age, sex,locations and to evaluate the predominant radiographic features. The incidence of tumors occurring in theextremitis is 90 percent of total 141 patients. The majority of tumors were located in the metaphses of the longtubular bones. About sixty percent of the patients were in the second decade of life. The increment of the levelof serum alkaline phosphatase was observed in 76(67%) out of 114 patients. It is considered that thoractic CT scanmight be helpful for the evaluation of metastases to lungs, because the detection rate of lung metastasis was 20percent among 30 cases by CT, being disclosed higher than by conventional radiographs. Of the 92 patientsavailable for radiographic analysis, predominantly osteolytic lesions were disclosed in 17 cases (19%).Preoperative radiographic impression was not the osteosarcoma in 8 out of 17 patients with purely osteolyticosteosarcoma, It was meant that the radiographic diagnosis was difficult in each case of predominantly osteolyticlesions. The patterns of periosteal reaction were variable, and there was no evidence of periosteal reaction inseventeen patients (18%). Both the cortical destruction and , the intralesional calcification were observed in 85percent of 92 patients with osteosarcoma. Extraskeletal tumor shadow was observed in 79 percent of 92 patientswith osteosarcoma, but either the calcification or ossification was detected in only 55 patients among 73 paitentswith soft tissue tumor shadows. Only 7 patients had a pathologic fracture, all in the femur.