Mammary cancer is one of the solid malignancies, which easily metastasizes to bone. The frequency of bone metastases of breast cancer has been reported to be 65-75% of all breast cancer patients, and, in autopsy example at Shikoku Cancer Center, metastasis was recognized to be 74.7%. There are many symptomatic signs of bone metastases, but hypercalcemia needs to be treated immediately. Hypercalcemia might be diagnosed precisely because a lethal symptom appears. For diagnosis, bone scintigram, simple X-rays, MRI, and CT scan were effective. Radiotherapy, surgery, chemotherapy, and hormonal treatments were useful to improve the symptoms from bone metastasis; in addition, bisphosphonates demonstrated a synergistic effect with chemoendocrine treatments. Bisphosphonates also reduced the incidence of symptom-related events in patients with bone metastasis.