Lung cancer is the first among all malignant tumors in human beings. Early stage lung cancer has good treatment effect and the survival rate can reach about 75% in three years. However, late stage lung cancer is less effective and has a shorter survival period. Therefore, the key lies in early detection and early treatment. There is no sensory nerve in the lung, so early lung tumor can be asymptomatic. When symptoms appear, such as cough, blood in sputum and chest pain, the tumor is often larger, so lung cancer is very hidden. Therefore, my suggestion is that annual or twice-yearly health checkup is a must. No matter how rich or poor you are, no matter how good you feel about yourself. Time is life, early detection and early treatment is the key to treat all diseases. Regarding the treatment of lung cancer, surgery is preferred if it can be removed surgically, because surgery is the most effective treatment among all. In case of advanced lung cancer, surgery can still be considered if radical resection can be achieved by local invasion. If the tumor is widely metastatic and cannot be resected radically, chemotherapy, radiotherapy, targeted therapy, biological therapy and symptomatic support therapy can be considered. At least it can achieve the purpose of prolonging the survival and improving the quality of life. I have met some patients and their families who are overly pessimistic and desperate after learning about their disease, and even give up treatment. In fact, it is not necessary, because there is hope only if one does not give up. If one gives up and despairs, there is no way for the most brilliant physician to help him. Everyone knows that prevention is better than cure, so how to prevent lung cancer? Or what factors are associated with lung cancer? Current research results show that lung cancer is related to genes, smoking, air pollution, water pollution, toxic food, personal character and life encounters. Where smokers are 17 times more likely to get lung cancer than non-smokers! That’s the most conservative number! Including second-hand smoke. So stay away from cigarettes! In conclusion, the key to lung cancer is to have good living habits, good health awareness, annual health checkups, early detection and early treatment, and prevention!