Radiographic and scintigraphic analysis of osseous system were performed in 152 cases of metastatic bone tumors with definite primary sites of malignancies. Bone involvement by hematologic malignancies was not considered in this study. RESULTS : 1. Among total of 152 patients, 100 patients were male and 52 patients were female. 2. Regarding age distribution, 6the decde was the peak and 5th to 7th decades were the majority. 3. Among total of 141 patients who underwent both bone scintigraphy and conventional bone radiography, 70 patients were scintigraphically positive and radiographically negative. Only 2 patients were scintigraphically negative and radiographically positive. 4. Lung cancer was the leading cause and stomach cancer, breast cancer, prostate cancer and hepatoma were in the decreasing order of causes. In male, lung cancer was the leading cause of metastatic bone tumor. Prostate cancer, stomach cancer and hepatoma were in the decreasing order of causes. In female, reast cancer was leading cause and stomach cancer, uterine cervix cancer and lung cancer and lung cancer were in the decreasing order of causes. 5. The ribs, spine and pelvis were mostcommoly involved. Skull, femur and humerus were also involved frequently. Metastasis distal to the knees and elvows occurred less frequently. 6. Osteolytic metastasis occurred most frequently. Among total of 61 patients with osteolytic metastasis, lung, stomach, breast and liver were metastasis, lung, stomach, breast and liver were the frequent primary sites of decreasing order. Among total of 16patients with osteoblastic metastasis, prostate, lung and stomach were frequent primary site of decreasing order. Among total of 10 patients with mixed metastasis, breast, stomach and prostate.