The smoking rate of the Japanese population has declined by approximately 30%. In Japan, the generations including many heavy current/past smokers are still aging, and the population composition is shifting to older. Therefore the number of COPD patients in Japan will increase over the next 20 years. The current prevalence of COPD in Japan is estimated to be approximately 9% and aged 40 years or older. As shown in the Takahata Study, the impact of decrease in pulmonary function on the health status is tremendous among the Japanese population with regard to mortality of all-cause and cardiovascular diseases. The prevention of adolescents from smoking, the promotion of those who have quit cigarette smoking, the improvement of understanding of COPD in the general population, and the early detection of COPD patients are all important to reduce the social damage brought on by COPD.