Demographic indicators are an essential element in considering various problems in the social economy, such as predicting economic fluctuations and establishing policies. Although literature extensively discusses the growth of the world population or issues pertaining to its aging, it has given little to no attention to population structures and transition patterns while considering compositional data problems. This study considers the characteristics of compositional data to examine the transition of the world population structure. The Aitchison distance examines the similarity of the world population structure from 1990 to 2080 and that of countries and regions in 2015, and creates maps to illustrate the results. Accordingly, the results identified the following countries and regions as epitomes of the world’s population structure through different periods: India, Northern Africa and South Africa, in the 1990s, South America in 2015 to 2030, Oceania and Northern America in 2040, Uruguay and Puerto Rico in 2050 to 2060, and Italy and Japan in the distant future.