Abstract: Objective : To study the influence of adjuvant chemotherapy followed by endocrine therapy on the survival rate of ER-positive postmenopausal breast cancer patients after modified radical mastectomy, retrospectively. Methods : ER-positive postmenopausal breast cancer patients were divided randomly into two groups, and were treated with chemotherapy followed by endocrine therapy (combined group) and endocrine therapy alone (endocrine group), respectively. The patients in combined group (N-67)received CMF(CTX+MTX+5-FU) or CAF(CTX+ADM+5-FU) for 6 courses of treatment, then tamoxifen (TAM) for 5 year orally; the patients in endocrine group (N-59) received tamoxifen (TAM) alone for 5 year orally. Results : The 5-year disease-free survival rates of the combined group and endocrine group who with stageⅡ、Ⅲ or≥4 axillary lymph node metastasis were 82.7%, 46.7Y, 58.3Y, 28.1%, 63.9%,28.7%, and the 5-year overall survival rates were 86.4%、 49.5%, 61.1%、 33.8%, 69.8%、34.8%, respectively (P<0.05). No significant difference was observed in the patients with stage I and those with <4 axillary lymph node metastases (P >0.05). conclusion : For ER-positive patients, the efficacy of chemotherapy followed by endocrine therapy is superior to endocrine therapy alone in the patients with stage ⅡⅢ and those with ≥4 axillary lymph node metastases.