Objective：To investigate the expression of β-TrCP in breast cancer tissues and its effect on prognosis of patients with breast cancer. Methods：β-TrCP expression in 56 samples of breast cancer and normal tissues and the corresponding samples of tumor-adjacent tissues were detected by immunohistochemistry. The correlation between β-TrCP expression and prognosis was analyzed. Results：The expression of β-TrCP in breast cancer tissues was significantly up-regulated compared with that of the normal tumor-ad－jacent tissues（χ2=37.333，P=0.000）. Clinicopathological evaluation suggested that β-TrCP positive expression was associated with ER positive（P=0.002），PR positive（P=0.004），lymph node metastasis（P=0.007） and TNM stage（P=0.004）. Five-year survival rate was 100%（16/16）in patients with negative expression of β-TrCP and was 72.5%（29/40）in patients with positive expression of β-TrCP（95%CI=0.559 to 0.837）. Results of log-rank test of statistical significance（P=0.015）. Multivariate Cox regression analysis revealed that β-TrCP positive expression was an independent factor for predicting poor prognosis in breast cancer（P=0.005，RR=0.287，95%CI=0.120-0.683）. Conclusion：High-expression of β-TrCP is correlated with the poor prognosis in breast cancer，suggesting β-TrCP may play a key role in development and progression of breast cancer.