Certain aspects of forming present-day Ukraine pension systems have been analyzed. It is noted that basic pension security mechanism is not only a diversified source for pension payment formation but also employs a high potential for formation of national investment resources, financial market development and growth of economic activity. The study is based on the confirmation that there is relationship between effective operation of pension system and the country’s demographics. Within the scope of work demographic data were collected, generalized and grouped in the context of pension systems under consideration. On the basis of comparison study of the main methodologies of formation the demography indicators, similar problems and adverse trends related to basic pension security development have been identified. It is emphasized that solution of these problems shall be by means of settlement of social development system imbalances. Necessity for generating predictive demographic trends in the long-term is regarded. As part of the study a complex of general scientific and statistical methods was used, such as data generalization, grouping and comparison. Abstractive generalizations and conclusions were being drawn in terms of logical method. Proposals have been developed for improvement of the concept of present-day pension systems of the countries under consideration for the purposes of further social and economic development of Ukraine towards accomplishment of social tasks.