Objective To investigate the expression of matrix metalloproteinase 2 (MMP2) and MMP9 in the breast cancer and its relationship with tumor invasive potentiality,node metastasis and prognostic significance.Methods 130 cases of breast cancer and 10 cases of breast benign disease were studied by immunohistochemical staining with MMP2,MMP9 monoclonal antibodies.Results The positive expression rate of MMP2 and MMP9 were 83.08％ (108/130) and 71.54％ (93/130) in the breast cancers,which was significantly higher than those in breast benign disease ( P ＜0.01 ).The expressions of MMP2 and MMP9 obviously increased with tumor sizes and clinical staging( P ＜0.05,P ＜ 0.01 ).Over expression of MMP2 and MMP9 in the breast cancers with axillary lymph node metastases were significantly higher than those without lymph node metastases ( P ＜ 0.01 ).Conclusions The expression of MMP2 and MMP9was closely correlated to lymph node metastasis,and may act as markers for lymph node metastasis and prognostic in breast cancer.