Purpose To investigate the protein expression of breast cancer susceptibility gene (BRCA1) in triple negative breast canc-er ( TNBC) and to analyze the prognostic impact on outcome of TNBC by BRCA1 protein. Methods The expression of BRCA1 and p53 in 95 cases TNBCs was detected by immunohistochemistry. The correlation analysis and evaluation of prognosis were conducted in consideration of patients clinical and pathological characteristics. Results The positive rate of BRCA1 protein expression in TNBCs was 31. 6%. Compared with BRCA1 negative expression, those patients with BRCA1 positive expression were associated with younger age (P=0. 047) and higher expression of p53 (P=0. 001). There was no significant difference in outcome between BRCA1 positive and negative expression (HR=1. 10,95%CI=0. 552~2. 235, P=0. 769). Conclusion The expression of BRCA1 protein may have no impact on the outcome of TNBC. There is possible correlationship between p53 pathway and BRCA1 in inhibiting tumor growth.