There will be a rapid surge in research about molecular residual disease (MRD) for solid cancer in the near future. However, MRD differed significantly between tumor types and between contexts; there continues to be a considerable lack of awareness and knowledge about using MRD in lung cancer. Hence, this study aims to investigate the value of MRD in NSCLC patients who underwent complete resection. Preoperative blood sample (20ml), tumor tissue and dynamic postoperative blood samples (20ml) are collected continuously for MRD detection. The follow-up was performed once every 3 to 6 months. The primary objective of this study is to assess the prognostic value of MRD for stage I-IIIA NSCLC patients after complete resection.