It has been hypothesized that damaged arm lymphatic drainage is associated with the arm lymphedema after axillary lymph node dissection (ALND). However, the majority of breast cancer patients with complete ALND has not suffered from arm lymphedema, which appears to be due to the residual arm lymph nodes that has not been removed in the axillary dissection. With the compensation of the residual arm lymph flow above the level of axillary vein, the arm lymphatic drainage could keep balance and remain normal function. This arm lymphedema prediction model that included the protective factor, the proportion of arm lymph flow above the level of axillary vein, allows intraoperative intervention to be performed for the high-risk group. The arm lymphatics of these distinguished patients would be preserved to eliminate the occurrence of arm lymphedema in this study.