Abstract: Objective: To study the clinical significance of preserving intercostobrachial nerve(ICBN) during the axillary lymph nodes excision in breast cancer operation. Methods: Sixty-one patients with stages Ⅰ and Ⅱ breast cancer were divided into treatment group(30 cases) and control group(31 cases) . ICBN was regularly resected in operation in control group, ICBN was preserved in axillary lymph node dissection operation in treatment group. Patients in both groups were treated as breast cancer regular therapy and followed rehabiliation exercise after operation. Results: The incidece of abnormal sense on medial upper arm in one, three and six months after operation was 16. 7%, 6. 7%, and 6. 7%, respectively, in treatment group, which was significantly lower than that 77. 4%, 64. 5%, and 58. 1%, respectively, in control group(P ＜ 0. 01) . Conclusions: Preserving ICBN in the axillary lymph nodes excision in breast cancer operation can reduce the incidence of abnormal sense on medial upper arm and improve life quality.