Stage 1a1 lung cancer refers to stage ⅠA1 lung cancer, whether patients need chemotherapy after surgical resection needs to be decided according to their actual condition and surgery. According to the clinical diagnosis and treatment guideline of lung cancer of Chinese Medical Association Oncology Branch, for non-small cell lung cancer stage ⅠA1 patients with complete resection and negative margins, chemotherapy is not needed after surgery, and regular follow-up is recommended; if incomplete resection or extra-peripheral infiltration of lymph nodes is found in the surgery, or if the tumor remains are visible to the naked eye, then reoperation is needed, and radiotherapy should be considered as a second option. As for small cell lung cancer stage IA1 patients, after using radical surgery, they usually need to disable adjuvant chemotherapy. For lung cancer patients, whether chemotherapy is needed after surgery should be decided by professional physicians after evaluation, and individuals should actively cooperate with them. In addition, after the treatment, the patient should follow the doctor’s instructions for timely review.