Abstract： Objective To study the clinical significance and the feasibility of detection in exhaled breath condensate (EBC) by study on p16 gene mutation in EBC and lung cancer tissue.Methods The lung cancer tissue and EBC specimens of 30 cases of non-small cell lung cancer (NSCLC) were collected,the EBC specimens of 20 cases of physical health were colleted at the same time.DNA of lung cancer tissue was extracted from resecting of operation in NSCLC patients,the β-actin gene fragment of EBC specimens was amplified positive and DNA of lung cancer tissue was extracted and exon 1,2,3 of p16 gene were amplified by PCR amplification and DNA gene sequencing method,using DNASTAR software for alignment of mutations.The results were statistically analyzed.Results ①In the EBC of 30 cases of NSCLC patients,β-actin gene fragment of 26 cases were amplified positive,p16 gene mutations were detected in nine cases,mutation rate was 34.6％.p16 gene mutations of patients were detected in the EBC and lung cancer tissue.②p16 gene mutations were detected in 15 of 30 cases of NSCLC tissues,mutation rate was 50.0％.o16 gene mutation was not detected in adjacent cancer tissues.③In 9 cases of NSCLC patients,p16 gene mutations were exon 1 of three cases,exon 2 of five cases,exon 3 of one case in EBC.In 15 cases of NSCLC patients,p16 gene mutations were exon 1 of four cases,exon 2 of eight cases,exon 3 of three cases in tumor tissues.④In 26 cases of NSCLC patients,β-actin gene was amplified positive in EBC.Mutation rate of p16 gene was 25.0％ (3/12) in Ⅰ stage,mutation rate of p16 gene was 28.6％ (2/7)in Ⅱ stage,mutation rate of p16 gene was 57.1％(4 /7)in Ⅲ stage ( P ＞0.05).Mutation rate of p16 gene was 42.9％ (6/14) in squamous carcinoma,mutation rate of p16 gene was 25.0％(3/12)in adenocarcinoma ( P ＞0.05).⑤In EBC and tissue of lung cancer of the same patients,the exon type,mutation way and mutation type and codon of p16 gene mutations were identical.Conclusions The mutation of p16 gene is detected in EBC and tissue of NSCLC patients.EBC and tissue has a high degree of consistency.Detection of mutations p16 gene in EBC can be used as a simple,rapid method for the diagnosis of lung cancer.