Objective To study the clinical significance of claudin-1, 3, 4 protein in breast carcinoma (BC).Methods From May 2013 to April 2014, Luhe hospital pathology specimens, including breast cancer (BC) tissues and corresponding normal breast tissues (NB) in 81 cases were collected, claudin-1, 3, and 4 of breast cancer patients' age, location, size, hormone receptor status, Ki67 proliferation, lymph node metastasis, vascular invasion and clinical stage were analyzed.Results The expression of claudin-1, 3, 4 in BC was lower than that of in NB.The expression of Claudin-1 in cancer (79.0%) and paraneoplastic expression (84.0%) showed no statistically significant differences (χ2=0.655,P>0.05).The expression of claudin-3, 4 had a statistic significance between BC(54.3%,77.8%)and NB (85.2%,92.6%)(χ2=18.290,χ2=7.043,P<0.01).Compared with the expression in no lymph node metastasis group(42.3%,61.5%), claudin-3, 4 highly expressed in lymph node metastasis group(82.8%,93.1%), and had a statistically significant difference between the two groups (χ2=0.365,χ2=0.322,P<0.05).The expression of claudin-3 also had a statistical difference between stage I (16.7%)and stage II/III(44.4%)(χ2=0.284,P<0.05);the expression of claudin-1 was not related with clinicopathologic factors.Conclusion Claudin 3, 4 protein have a vital role in promoting the tumorigenesis, invasion and metastasis of BC, and can be act as a biological marker of BC development, progression, and prognostic evaluation.