Objective:To investigate the protein expression of Clusterin in breast cancer and its clinical significance. Methods:Clusterin expression were examined by immunohistochemical staining method in 60 cases with breast cancer,10 cases with benign pathological changes and 10 cases with normal breast tissues. Results:The positive rates of Clusterin in normal breast tissues,benign pathological changes and breast cancer tissues were 0%,10% and 78.33%, respectively. The expression of Clusterin in breast cancer was much higher than that in normal breast tissues(P < 0.05) and benign pathological changes(P < 0.05). The expression of Clusterin in breast cancer tissues was closely related to histological type(P < 0.05) and lymph node metastasis(P < 0.05). but no correlated to the age,tumor size and clinical stage. There was a negative correlation between ER,PR and Clusterin. There was no correlation between C-erbB-2 and Clusterin. There was a positive correlation between p53,Ki67 and Clusterin. Conclusion:Clusterin may play an important role in the biological characteristics of breast cancer by the antiapoptosis pathway. It may be used as a potential therapeutic target for breast cancer.