Regional capitals are an important category of cities in the South of European Russia, where more than a quarter (25.6 %) of the population of the macroregion lives and a significant demographic potential of the region is concentrated. The south of European Russia includes regions with natural population growth which are rare for modern Russia, regions and capitals with high rates of migration growth, as well as territories with an unfavorable demographic situation. To study territories with such a differentiated multidimensional demographic situation, geoinformation technologies were used to consolidate statistical data from various sources, conduct spatial analysis, model and visualize the processes under study. The realization of this request is possible with the use of atlas information systems (AIS), which are actively used in various subject areas, including the study of socio-economic and demographic processes. As part of the research, we have developed an atlas information system “Regional Capitals of the South of European Russia”, consisting of 2 main blocks: a structural block includes a basic GIS platform, a cartographic framework, a geodata database and a modeling and visualization unit responsible for the preparation of cartographic and visual models. AIS contains 6 thematic sections: ethnodemographic and migration processes (“Population size”, “Demographic indicators”, “Migration indicators”, “Ethnic structure of the population”), “Covid-19” (contains indicators for the sick, deceased, cured of coronavirus infection, natural population growth), “Big Data (Big Data)” consolidating indicators on the real estate market and the urban environment quality index as important factors in the formation of the demographic and migration situation. This makes it possible to conduct modeling, thematic mapping, creation of various visual plots for comprehensive complex spatial analysis. It allows to increase the level of analytics in the process of making economically determined management decisions in the regional capitals of Southern European Russia. Additionally, the possibility of integrating AIS with Web services is described.