Abstract: Objective To investigate the expression of raf kinase inhibitor protein (RKIP) and matrix metalloproteinase-2（MMP-2）in non-small cell lung cancer(NSCLC) and their correlation with the clinicopathologic features and prognosis. Methods RKIP and MMP-2 protein expression of 83 cases of lung carcinoma specimens and non-tumor lung samples around were investigated by using immunohistochemistry. Results Immunohistochemistry results revealed that of the 83 cases,there was a low expression between RKIP and a high expression of MMP-2,20.5% (17/83) and 69.9% (58/83) respectively.There was correlation between RKIP and MMP-2 protein expression and differentiation of tumor，TNM staging，development of lymph node metastasis and the survival time（P<0.05,respectively ）.RKIP expression was negatively correlated with MMP-2 expression in NSCLC（P<0.05）；the 2-year survival rate with low level of RKIP protein was much more decreased than those with high level of MMP-2 protein（P<0.05）. Conclusion The low expression of RKIP was closely correlated with invasion and metastasis of NSCLC.RKIP may be a NSCLC metastasis suppressor, whose down-regulation expression would lead to the over-expression of MMP-2,as a result,promoting the invasion and metastasis of lung carcinoma cells.