Objective: To investigate the expression of the new microtubule-binding protein NuSAP in breast cancer tissue and its clinical significance. Methods: Fifty specimens of breast cancer tissue together with 37 specimens of the adjacent normal breast tissue (>5 cm away from the tumor) and 20 breast specimens of benign disease were collected. The expressions of protein and mRNA in these tissues were detected by immunohistochemical staining and real-time quantitative PCR, respectively. The relations of NuSAP expression with clinicopathologic characteristics of breast cancer patients were analyzed. Results: Both NuSAP protein and mRNA expression levels in breast cancer tissue were significantly higher than those in adjacent normal breast tissue and breast tissue from benign disease (all P<0.05); both NuSAP protein and mRNA expression levels were significantly increased in breast cancer tissues with axillary lymph node metastasis and positive HER-2 expression (all P<0.05), while they were irrelevant to age, menopausal status, and expressions of ER, PR and Ki-67 (all P>0.05). Conclusion: NuSAP expression is increased in breast cancer tissue, which may be closely associated with the occurrence, development and progression of breast cancer.