Abstract: Objective To explore the relationship between Napsin-A expression and epider-mal growth factor receptor (EGFR)genes in non-small cell lung cancer (NSCLC)tissue.Methods Napsin-A expression in 89 adenosquamous carcinoma tissues of the lung was detected by immunohisto-chemistry,and the expression of EGFR genes in the tissues above was also detected by ARMS kit.The relationship between Napsin-A expression and EGFR was analyzed.Results The Napsin-A positive rates of adenocarcinoma and squamous carcinoma in NSCLC tissue were 96.2% and 5.6%,respec-tively,and there was statistical significance between them.The mutation rate of EGFR gene in lung adenocarcinoma tissue was 54.7%,while that of the patients with positive Napsin-A expression came up to 100.0%.The mutation rate of EGFR gene in lung squamous tissue was 5.6%,while that of the patients with positive Napsin-A expression came up to 50.0%,in which significant difference was presented by comparison to them.Conclusion Napsin-A is highly expressed in lung adenocarcinoma tissue,and the EGFR mutation rate of patients with positive expression in adenosquamous carcinoma is also high.Hence,for the patients with positive Napsin-A expression,it should be recommended to de-tect EGFR genes.