Abstract: Objective To investigate the expressions of β-catenin， lymphoid enhancerbinding factor-1（LEF-1） and PTEN in breast cancer， and analyze their relationship with clinicopathological features and the correlation among the three proteins. Methods The expressions of β-catenin， LEF-1 and PTEN were detected by immunohistochemistry in 65 cases of breast cancer tissues， 30 cases of breast fibroadenoma tissues and 30 cases of adjacent normal breast tissues. The clinicopathological features and relevance of three proteins were analyzed. Results In adjacent normal tissues， breast fibroadenoma tissues and breast cancer tissues， the positive expression rate of β-catenin was 26.7％（8／30）， 33.3％（10／30）， 61.5％（40／65）, respectively； the positive expression rate of LEF-1 was 10.0％（3／30）， 23.3％（7／30）， 56.9％（37／65）, respectively； the positive expression rate of PTEN was 90.0％（27／30）， 83.3％（25／30）， 41.5％（27／65）, respectively； and the differences were statistically significant（P＜0.05）. The expressions of the three proteins in breast cancer tissue had no correlation with age， tumor size and tumor site（P＞0.05）， but with TNM stage and lymph node metastasis（P＜0.05）. The expression of βcatenin and LEF1 in breast cancer was positive correlated（r=0.845，P＜0.05）， while βcatenin and PTEN was negative correlated（r=-0.874，P＜0.05）. Conclusion The abnormal expressions of β-catenin， LEF-1 and PTEN are closely related with the occurrence， progression， invasion and metastasis in breast cancer. The combined detection of the three proteins may play an important role in judging biological behavior of breast cancer.