Abstract: From 1954 to 1989, 50 cases of male breast cancer were treated surgicallyin Tianjin Cancer Hospital, accounted for 0.71% of 7050 breast cancers cases treated during the same period. There were 8 cases of stageⅠ，21 stageⅡ, 20 stage Ⅲ cases and 1 bilateral breast cancer. 6 extended radieal mastectomies, 31 traditional radical mastectomies,6 modified radical mastectomies, 5 simple mastectomies and 2 lumpectomies were performed. 5-year survival rate of all the cases was 78.7%, 10 year survival rate was 31.6%. Meanwhile, Factors of occurence and prognosis of male breast cancer were discussed in this essay.Prognosis of male breast cancer was related to classification. pathologieal type. State of axillary lymph nodes metastasis and adjuvant therapy. No relation was found with operation type. The factors which affect occurence of male breast cancer might be (1)liver disease(2)testis dis-ease (3)radiation damage(4)estrin treatment(5)grnecomasty(6)family history of cancer.