Provided are a biomarker related to detection of lung adenocarcinoma and a use thereof. Also provided is a method for in vitro detection of lung adenocarcinoma, comprising: acquiring a first mutation level from mutation levels of one or more biomarkers at a first site of a subject, wherein the biomarker comprises at least one the following genes: TP53, EGFR, LRP1B, KRAS, PTPRD, STK11, SMAD2, PIK3CA, BRAF, FLT1, RHPN2, GLI3 and MRC2； comparing the first mutation level with a first reference level； and when there is a distinct difference between the first mutation level and the first reference level, determining that the subject has a lung adenocarcinoma, wherein the first reference level is a mutation level of the biomarker at a first site of a normal individual.
