Background: Triple negative breast cancer (TNBC: Estrogen receptor, progesterone receptor and HER2 expression negative breast cancer) has not been discovered specific treatment target and often fall into poor prognosis.We proposed to reveal the character and the prognosis of TNBC in Japanese breast cancer patients.Material and Method: Two hundred nineteen TNBC patients treated between January 2001 and June 2009 were included in this study.Carcinoma in situ, Stage (++) W, occult breast cancer and bilateral breast cancer patients were excluded from this study.Result: Patients ranged from 22 to 87 years old (median 57 y.o) with follow-up period of five to 115 months (median 45 months).Invasive ductal carcinoma was found in 161 patients, invasive lobular carcinoma in ten, invasive apocrine carcinoma in 32, matrix producing cancer in seven and the other subtypes in nine.Lymph vascular invasion was detected in 83 cases (37.9%) and lymph node metastasis was found in 58 cases (26.5%).Adjuvant or neoadjuvant chemotherapy was performed in 175 patients (80%).Thirty six out of 219 patients had recurrence.Time to recurrence ranged from 2.7 to 50.8 months (median 20.5 months) and 30 patients (83.3%) had recurrence within three years.The first recurrence site was lung or pleura in 15 cases, liver in six, bone in ten, lymph node in six and brain in three.Statistical significant risk factors for the recurrences were tumor size, lymph node metastases and lymph vascular invasion.The breast cancer associated death after the recurrence was observed in 27 patients, and the significant factor which affect survival period after recurrence was disease free interval.Conclusion: Relapse tends to be occurred within three years in TNBC patients.The construction of a new treatment strategy is urgent business especially for the patient relapsed within short disease free interval.