Objective：To investigate the expression of MMP-13 in breast cancer tissues and its relationship with clinical prognosis of patients. Methods: Tissue microarray and immunohistochemical SP method were used to detect the expression of MMP-13 in 183 specimens of breast cancer. The association between the expression of MMP-13 and the clinicopathologic parameters of patients was analyzed; the association between MMP-13 and the prognosis of breast cancer was also discussed based on 10 years’ follow-up data. Results: The positive rate of MMP-13 in the breast cancer tissue (54.1%) was significantly higher than that in the benign breast tissues (13.3%,P<0.01).MMP-13 expression was significantly correlated with the clinical TNM stage, histological grade and lymph node metastasis status of the malignancy(P<0.01), but was not correlated with patients’ age, tumor size, pathological type, period status, and the status of estrogen receptor and progesterone receptors.The 10-year survival rate of patients with over- expression of MMP-13 was lower than patients with low MMP-13 expression(P<0.01). Conclusion: MMP-13 expression is upregulated in breast cancer tissues, which is an indicator of poor prognosis of patients.