Diagnosis and treatments of bone metastasis were reviewed with clinical experiments in National Medical center Hospital. As for diagnosis of bone metastasis, early detection of bone metastasis was significantly improved by using bone scintigrams recently progressed. But the results of reviews suggest the possible improvements in diagnosis of bone metastasis. X-CT (X-ray Computed Tomography) for diagnosis of bone metastasis is advantages in three dimensional delineation of the extend and spread of bone lesions in bone marrow over bone scintigram. MRI (magnetic resonance imaging) has clinically been developed since 1981, does not directly represent bone structures but soft tissues in bone marrow, giving useful information concerning changes and spread of metastatic bone tumor not only inside the bone but also around it. MRI is now in technical progress and expected some improvements, could be expected in early diagnosis of bone metastasis. Regarding as treatment, we have individually to choose from radiotherapy, hormonal therapy, chemotherapy, surgical therapy according to clinical circumstances and does themselves. Radiation treatment is widely approved not only much effective in relieving the pains from bone metastasis, but also it is considered at the first choice in treatment of the spinal cord paresis by vertebral metastasis, because of frequently bringing good therapeutic effects.