The causes, risk factors and sequelae of mastectomy were studied, and the physical therapy approaches on post-mastectomy was discussed in this study. It was found that the patients taken mastectomy have experienced pins and needles in muscle, weakening of muscle, pains, deterioration of motion in joint region and activities of daily living, psychiatric sequelae, and etc even after the conservertive therapies like the chemical therapy, radiotherapy, immunotherapy, and hormone therapy. However, few study on the physical therapy approaches for patients with breast cancer has been carried in Korea at present. The followings were proposed as the physical therapy approaches. 1. Shoulder joint motion approach to relax the limit of range of motion 2. Control of breathing exercise for dealing with removal of the pectorailis muscle 3. Method to reduce the edema of arms for tackling the cut of lymph node 4. Method to reduce pains, pins and needles 5. Support home exercise program after discharging from hospital, sexual life and pregnancy, and activities of daily living training method.