Abstract: Objective To investigate the expression and clinical significance of metallothionein(MT) in non-small cell lung cancer. Methods Immunohistochemical methods are used to detect the expressions of MT in 68 cases of non-small cell lung cancer and 25 cases of benign lung disease.The relationships between MT expression and clinicopathological factors or patient prognosis and correlations between MT, GST-π, and TopoⅡwere analyzed. Results The expression level of MT was significantly higher in NSCLC than in benign lung disease. There was significant correlation between MT expresssion and age, tumor differentiation. The survival of the patients with high expression of MT as compared to low expression of MT was shorter. No significant correlations were observed between MT and GST-π, MT and TopoⅡ, GST-π and TopoⅡ. Conclusion MT was over expressed in various degrees in NSCLC tissues, and related to some biology behaviour and prognosis of NSCLC.