There is no authoritative reference for how long the survival period of pemetrexed for lung adenocarcinoma is, but overall, the five-year survival rate of this disease is less than 20%. Lung adenocarcinoma is one of the common types of lung cancer, and its cause is not yet clear, but the main causative factors include smoking, air pollution, ionizing radiation, diet, etc. The common clinical symptoms include cough, bloody sputum, chest pain and fever, shortness of breath, etc. The conventional treatments for this disease include surgery, chemotherapy, radiotherapy, targeted therapy and shortness of breath. Conventional treatments for this disease include surgery, chemotherapy, radiotherapy, targeted therapy and immunotherapy, etc. There is no authoritative reference for how long the survival period of lung adenocarcinoma can be treated with pemetrexed alone. Lung adenocarcinoma patients should actively cooperate with physicians for relevant treatments and follow the doctor’s instructions to use medication on time and according to the dosage in order to prolong the survival period.