Abstract: Objective : To explore the clinical value of methylation-specific polymerase chain reaction on the diagnosis of Lung cancer. Methods : 56cases of pathological tissues excised in operation corresponding bronchoalveolar Lavage fluid (BALF) and sputum were obtained from hospitalized patients, among them, 32cases were lung cancer, 24cases were benign Lung diseases. After general dealing the samples, DNA extracting and PCR amp lifiation, the PCR products were dyeing with EB and observed under ultraviolet Lamp. Results : among 32 Lung cancer tissues, 14cases (43.8%) were found abnormal methylation in promoter area of p16 gene, 9cases (64.3%) were obtained methylation in corresponding BALF, 5cases (35.8%) in corresponding sputum, while 24cases of benign Lung diseases were not found methylation neither in tissues excised in operation nor in corresponding BALF and sputum in p16 gene. Conclusion : MSPCR has great speciality on the detection of abnormal methylation in BALF and sputum of patients with lung cancer; MSPCR is a newly and with high potential early diagnostic technique in lung cancer.