The decrease in birth rates and the increase in life expectancy cause a significant change in the global age structure. There have been some changes in economic life with the change in the ratio of age groups in the total population, especially the increase in the proportion of the elderly population. These changes have led to the differentiation of subjects such as labor supply, savings, consumption, public expenditures and human capital among young, working age and elderly population groups. It is stated that the change in population will affect economic growth through three mechanisms as consumption and savings models, public social expenditure and human capital. In this study, it has been tried to explain how population aging will affect national income. In this context, the relationship between demographic variables and national income was examined by panel data analysis method using the data of G20 countries. The results of the analysis show that as the ratio of the working age population in the total population increases, the national income increases. In addition, it has been concluded that the increase in the elderly population in the total population also increases the national income.