The article considers issue of expediency of discovering potential of national and international public associations on building up social health of citizens in the states members of the Eurasian Economical Union (EAEU). The problem is in absence of scientifically grounded sociological demographic approach to applying capabilities of public sector in building up people’s social health. The study is based on official statistics of the EAEU, as well as on the results of public opinion poll by VCIOM (Russian Public Opinion Research Center). The analysis of the qualitative side of interpersonal relationships permitted to conclude that people’s circle of friendly communications is mainly concentrated on close relatives, helping to strengthen social health of citizens. The following concept was proposed: since rail and air transport initially suppose spatial movement of people over longer distances than road transport, there is probably tendency of increasing of social communications between persons located at significant territorial distance from each other. It is established that further research of potential of national and international public associations can become an important tool of determining current social demographic trends and developing recommendations to improve social health of citizens of the EAEU member states.