The duration of targeted drug therapy after surgery for early stage lung adenocarcinoma needs to be based on the patient’s tolerance as well as the progression of the disease. The usual course of treatment is 2 years, and some patients can last longer. Because the course of targeted drug therapy is relatively long, usually 2 years, replacement is due to tumor recurrence, patient intolerance or serious side effects. At present, there are many kinds of targeted drugs, and the therapeutic effect of the first, second and third generation of targeted drugs is still acceptable. If the patient develops drug resistance after receiving targeted drug therapy, he/she can change to other drugs according to the situation. If the patient does not have tumor enlargement or metastasis, the drug treatment can be continued for about 2 years. Moreover, more drugs and treatment programs targeting genetic changes are gradually being applied in the clinic.