Recent research data showed the concept that "surgery is still the main treatment for early non-small cell lung cancer (NSCLC)" now has new connotation: (1) Pure ground glass nodule (GGO) like lung adenocarcinoma should be regarded as a new clinical issue compared to solid tumors to avoid over-treatment. (2) The deep meaning of multidisciplinary pathological classification of lung adenocarcinoma should be fully understood to avoid over-diagnosis. (3) The T staging of lung adenocarcinoma mixed with GGO components should be correctly understood to avoid over-staging. (4) We should carefully understand the new data of relationship between lung resection extent and prognosis to avoid excessive resection. (5) Attention should be paid to the research progress of minimal residual disease (MRD) to avoid possible insufficient treatment.