Predicting relapse and overall survival in potentially resectable Stage IIIA-IIIB Non-small Cell Lung Cancer (NSCLC) patients remains challenging. It is now widely recognized that patients with detectable MRD have a worse prognosis than those with undetectable MRD. Therefore, investigators performed this prospective clinical trial to evaluate the predictive value of MRD with increased risk of relapse and improves prediction of outcome in potentially resectable Stage IIIA-IIIB NSCLC with neoadjuvant chemoimmunotherapy. In this study, investigators will pay more attention to the long-term follow-up time and dynamic monitoring of MRD. The predictive value of MRD with Disease-free survival (DFS) rate was observed as the primary endpoint. Besides that, the correlation of MRD with major pathologic response (MPR) rate, pathologic complete response (pCR) rate，event-free survival(EFS) rate and overall survival (OS) were observed as the second endpoints. Investigators hope it will provide a new insight for these potentially resectable Stage IIA-IIIB NSCLC with neoadjuvant chemoimmunotherapy.

Key Inclusion Criteria:

• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 2.
• Have previously untreated and histological examination confirms resectable stage II-IIIA/IIIB non-small cell lung cancer (according to the 8th edition of the AJCC TNM staging criteria), and the pathological type of squamous cell carcinoma and non-squamous cell carcinoma needs to be distinguished, and EGFR, ALK, and ROS1 should be negative for non-squamous non-small cell lung cancer
• Adequate organ function and expected survival time ≥ 12 weeks;
• Evidence of post-menopausal status or negative urinary or serum pregnancy test for female pre-menopausal patients.

Key Exclusion Criteria:

• Presence of mixed carcinoma component on histology.
• Patients with other active malignancies within 5 years prior to enrollment.
• Known active autoimmune diseases.
• Currently participate in an interventional clinical study treatment or have been treated with another drug or investigational device within 4 weeks prior to the first dose.
• Use of immunosuppressive agents within 14 days prior to the first dose of study treatment.
• Presence of other uncontrolled serious medical conditions.

Patient initially diagnosed with resectable stage III-IIIA/IIIB non-small cell lung cancer t the First Hospital of Jilin University.