In almost all countries and regions, lung cancer incidence and mortality rates are higher in men than in women. However, in recent years, the incidence of lung cancer in women has increased faster than that in men in some developed countries in Western Europe and North America. This may be related to the increase of female smokers. In addition, lung cancer in women is mainly adenocarcinoma, which is reported to be closely related to small environmental pollution in the kitchen (fuel, oil smoke, etc.). The incidence of lung cancer increases with age. After the age of 40, the incidence increases gradually. The mortality rate generally peaks at age 65 or 70. However, as the smoking population becomes younger, we should be alert to the tendency of lung cancer occurring in people under 30 years of age.