Abstract: Objective:To investigate the clinical and pathological characteristics of the mammary hamartoma.Methods:The pathological sections of 25 cases of mammary hamartoma were stained ordinarily and immunohistochemically.Their clinical and pathological features were analyzed retrospectively.Results:All the patients were female and their ages ranged from 18 to 51.Fourteen tumors were located in the left breast and 11 in the right.Most of the tumors were aponia local masses with well-defined borders.The tumor histologically consisted of ducts,lobules,fibrous stroma and adipose tissues.Conclusions:The mammary hamartoma is a special type benign tumor which is rarely seen and difficult to diagnose before and after surgery for the absence of specific clinical manifestations.The prognosis is usually satisfactory.