Inclusion Criteria:  Patients aged between 18 and 70 years Histological diagnosis of primary NSCLC Patients received curative surgery for primary NSCLC Tumor stage IB-IIA after curative-intent surgical resection ECOG score: 0-1 Participant is willing to use an acceptable form of contraception during the study. Participant is willing and able to give informed consent for participation in the study.  Exclusion Criteria:  The patient has received neoadjuvant therapy, including radiotherapy and chemotherapy, targeted therapy and immunotherapy Patients are unwilling or unable to receive the curative-intent resection Patients have or have had history of malignant tumor Patients who suffer from severe uncontrolled disease that require systemic treatment or considered unsuitable for participating this trial due to other reasons by the investigator Patients with severe gastrointestinal dysfunction, cardiac dysfunction, interstitial lung disease, etc. Laboratory test results showed inadequate bone marrow or organ function Blood transfusion during or within 2 weeks before the surgery History of alcohol abuse or drug overdose Pregnant or breastfeeding women Patients who are currently or have participated in any other anti-tumor clinical trials Inadequate baseline data, such as preoperative and postoperative blood samples (Lack of 2 consecutive blood test or a total of 3 blood samples), surgical tumor tissues, and ctDNA test.