Abstract: Objective:To investigate the epidermal growth factor receptor(EGFR) mutation in plasma and urine samples of patients with advanced lung adenocarcinoma,and to analyze the feasibility of detecting EGFR mutataion in urine. Methods:The plasma and urine cell-free DNA (cfDNA) in 60 patients with advanced lung adenocarcinoma were extracted with modified phenol-chloroform method. Mutant-enriched PCR coupled sequencing of cfDNA was used to detect the EGFR mutation. Results:Among the 60 cases, EGFR mutation was detected in the plasma of 12 cases including 7 deletion mutation in exon 19 and 5 mutation in exon 21,while the result was negative in the urine samples. In the plasma samples,EGFR mutation was correlated with the gender of the patients but not with the age or smoking history. Conclusions:EGFR mutation can be detected in the plasma samples of patients with advanced lung adenocarcinoma but not in the urine samples.