Abstract: Objective: To explore the efficacy of modified radical mastectomy on breast cancer. Methods: The clinical data of 78 patients who had received modified radical mastectomy for breast cancer were analyzed retrospectively. Results: One thousand three hundred and ten lymph nodes were removed from the 78 cases,with an average number of 16.8. Among them,gradeⅠlymph nodes accounted for 11 on the average,gradeⅡ 4.9 and grade Ⅲ 1.8. Three hundred and twelve of the lymph nodes were proved positive, with a positive rate of 23.82%. The follow-up time was 50 to 114 months,and the 5-year survival rate was 66.7%. Conclusions: The modified radical mastectomy is the main procedure for management of breast cancer,and the effect is confirmed.