Breast cancer is one of the most common malignant tumors in current world, which is the first cause of cancer death in women［1］. At present the treatment of breast cancer are surgery, radiotherapy, chemotherapy and endocrine treatment and targeted therapy, etc., and the gradually standardized comprehensive treatment method has improved the condition of patients with breast cancer. Upper limb lymphedema is one of the most common complications after breast cancer, whose reported incidence rate is about 6% to 14%. It affects the normal function of sick limb seriously, causing inconvenience for patients and lowering the quality of life. This article summarizes the research status on upper extremity edema caused by breast cancer and postoperative radiotherapy.