Seventy-seven cases of metastatic bone tumors are analysed, which has been confirmed by operation or biopsy at Severance Hospital, Yonsei University College of Medicine. The results are follows. 1. Primary site of metastatic bone tumor: Bony metastatsis from carcinoma of gastrointestinal tract was most frequent and 17 cases(22.1%). Among them, stomach cancer was 10 cases (13.0%), hepatoma 6 cases (7.8%) and esophageal cancer 1 case (1.3%). Second order of metastasis was lung and uterine cervical cancer and each was 8 cases(10.4%). And then metastasis from breast cancer was 6 cases(7.8%). 2. Frequently involved skeletons of metastatic site: Breast, stomach, prostate and uterine cervical cancer were more frequently metastasized to axial skeletons such as spines, pelvis and ribs. And lung cancer and hepatoma were more frequently to skull, femur and rib. 3. Type of metastasis in radiographic classification: The order of frequency which showed osteoblastic or mixed type of metastas s was stomach (5 cases, 35.7%) breast (3 cases, 21.4%) prostate (2 cases, 14.3%) lung (2 cases, 14.3%) melanoma (1 case, 7.1%) and bladder (1 case 7.1%) cancer. The order of metastasis which showed osteolytic one was cervix (8 cases, 28.6%), lung (6 cases, 21.4%), stomach (5 cases, 17.9%), skin (4 cases, 14.3%), breast (3 cases 10.7%), kidney (1 case, 3.55%) cancers and melanoma (1 case 3.55%). Among them, cervix, liver, skin and renal cancer were purely osteolytic type. 4. Radiographic findings in detail of analysis: Most frequent radiographic features of metastatic bone tumor was diffuse scattering, mottled and ill-defined bony rarefaction. Those showed solitary localized osteolytic lesion were metastasis from cervix(2 cases), bladder(1 case), liver(1 case) and lung(1 case) cancer in decreasing order of frequency. Those showed multiple localized osteolytic lesion were metastasis from liver(caseses), cervix(3 cases), skin(2 cases), breast(2 cases), lung (1 case) and bladder(1 case) ancer. These analysis were only included by radiographically and pathologically proven cases. There should be more expected cases being included, if routine bone survey should be done for cancer patient with conjunction of proven in autopsy. Screening bone scanning, using radioisotope is more recommended for the early detection of meastatic lesion which was unable to detect on plain X-ray film.