Lung cancer is one of the malignant tumors. The death rate and incidence are very high through the whole world. Aberrant methylation of p16 gene promoter is thought to be an early event in lung cancer development. To improve the sensitivity and specificity, the microfluidic chip method was established to detect the aberrant methylation of p16 gene. The plasma samples of lung cancer patients were detected. The p16 gene methylation can perhaps become a biomarker for early lung cancer. It may become a new and reliable method for early diagnosis of lung cancer.