Objective To analyze the clinicopathologic features of 747 cases of triple negative breast cancer.Methods 747 cases of operable breast cancer between March 2003 and Novenmber 2003 were analyzed.Immunohistochemistry was used to determine Her-2,ER and PR status.The patients were divided into the triple negative breast cancer group(ER negative,PR negative and Her-2 negative) and the non-triple negative breast cancer group.The clinicopathologic features of the two groups were compared.Results Of the 747 patients,21.3%(159/747)had triple negative breast cancer and 78.7%(588/747)had non-triple negative breast cancer.The percentage of cases with medullary type or grade Ⅲ was higher in the triple negative groups than in the non-triple negative group.There was significant difference in histological grade between the two groups(P0.05).Recurrence and metastasis of triple negative breast cancer group was higher than that of non-triple negative breast cancer group,but there was no significant difference(P=0.236).Conclusion Compared with non-triple negative breast cancer,triple negative breast cancer has a higher histological grade and a worse prognosis.