Many rotator cuff tears are operatively treated in recent years. Postoperative rehabilitation of rotator cuff repair is as important as diagnosis of disease or surgery itself. And it is a crucial factor on the prognosis of the surgery. For appropriate rehabilitation, surgeon should have knowledge about the anatomy and biomechanics of shoulder. The purposes of postoperative rehabilitation are to avoid additional injury, to decrease inflammation, to help healing process of collagen, to strengthen weak muscle, to recover decreased range of motion, to increase endurance of muscle and to protect the repair site and deltoid. These protocols must be individualized according to the condition of the patients.