Objective To study how to reduce the incidence rate of skin flap necrosis after the eradicative resection of breast cancer. Methods 45 patients with breast cancer underwent eradicative operation with new methods to prevent the necrosis of skin flap,and they were studied and compared with 1210 cases treated by traditional ways. Results With the new methods adopted, the necrosis rate of skin flap following eradicative operation of breast cancer was reduced from 45%(original)to 2%(present).Statistic analysis showed that there was outstanding difference between them. Conclusion In the eradicative operation of breast cancer,the key to prevent the necrosis rate of skin flap is:prevention of subaxillary lymphatic fistula, two tubular drainage set individually in subcostalis and subaxillaris, appropriate force of chest bandaging, proper thickness of skin flap and perfect suture without tension.