The course of Gefitinib tablets is mainly determined by the efficacy of Gefitinib tablets, and the general principle is to eat until the progression is dominant, or until the side effects are tolerated, that is, for advanced non-small cell lung cancer with EGFR gene mutation, the use of Gefitinib can be eaten until the disease progresses, that is, the lesion is more than 50% larger than before by the clinician’s judgment, lasts for 1 month or serious side effects are not tolerated, such as exfoliative dermatitis, severe hepatic impairment, etc. such as exfoliative dermatitis, severe hepatic impairment, etc. At this time, gefitinib treatment can be stopped and replaced with a 3rd generation treatment such as oseltinib or chemotherapy drugs, or with an anti-tumor angiogenesis treatment. In conclusion, the course of Gefitinib should be judged according to the efficacy or side effects.