In order to explore the impact of population structure changes on the level of economic growth in Hunan province, based on the analysis of population structure changes in Hunan Province over the years, a quantitative study on the effects of population structure index on economic growth is made by using stepwise regression method. The results show that the cultural and age structure of population are the important factors which influence the economic growth in Hunan province, and the high education level is the primary factor to promote the growth of economy; working-age population and children also have a significant positive effect on economic growth.