Abstract: Objective To detect the expression and significance of NapsinA，TTF-1,CK5/6,CK7 and P63 in biopsy specimen by bronchoscope of non-small cell lung cancer(NSCLC). Methods The expressions of NapsinA,TTF-1、CK5/6,CK7 and P63 were detected by immunohistoehemical SP method in 47 NSCLC of biopsy specimen by bronchoscope，and the clinicalpathological features of NSCLC were analyzed statistically. Results The positive rates of NapsinA,TTF-1 and CK7 were 100%（27/27）,100% (27/27) and 93%(25/27) in 27 cases of lung adenocarcinoma,respectively which was higher than CK5/6 19%(5/27)and P63 0(0/25)(P<0.05),respectively.The positive rates of CK5/6 and P63 were all 100%(18/18) in 18 cases of lung squamous cell carcinoma,respectively which was higher than NapsinA 0（0/18）、TTF-1 0(0/18) and CK7 11%(2/18) (P<0.05),respectively.Both showed significant increasing gradient. Conclusion NapsinA，TTF-1,CK5/6,CK7 and P63 expressions are important significance at the differential diagnosis between lung squamous cell carcinoma and adnocarcinoma in biopsy specimen by bronchoscope.