Abstract: Objective To study the expression of caveolin-1 and cathepsin D in non-small cell lung carcinoma (NSCLC) and their correlation with microvessel density (MVD) and clinicopathologic parameters. Methods Immunohistochemistry staining was used to detect caveolin-1,cathepsin D expression in 68 NSCLCs and 20 adjacent noncancerous lung tissues and CD34 expression in NSCLC.MVD was detected by CD34 immunostaining. Results The positive rate of caveolin-1 protein in NSCLC was significantly lower than those in adjacent noncancerous lung tissues (P=0.000).On the contrary,the positive rate of cathepsin D in NSCLC was significantly higher than those in adjacent noncancerous lung tissues(P=0.024).Caveolin-1 and cathepsin D expression were both correlated with higher TNM stage (P₁=0.001；P₂=0.008) and lymph node metastasis (P₁=0.032；P₂=0.001).MVD in the positive expression of caveolin-1 and cathepsin D were higher than those in the negative cases(P=0.000).The expression caveolin-1 was positively correlated with the expression of cathepsin D in the NSCLC(r=0.307；P=0.004). Conclusion caveolin-1 may have a dual effect in the NSCLC.High expression of caveolin-1 and cathepsin D may play a vital role in the progression of NSCLC and closely correlate with tumor angiogenesis.