Non-state pension funds play an important role in the development of the economy. The development of the system of non-state pension provision, which includes non-state pension funds, complies with the main aspects of the Ukraine – 2020 Sustainable Development Strategy. The importance of selecting investment areas for non-state pension funds results in the need to further explore and find ways to improve the investment process. The purpose of the article is to develop theoretical and methodological aspects of investing assets of non-state pension funds in bonds. The study object is the investment activity of non-state pension funds. The following methods are used: vertical and horizontal analysis, SWOT analysis, regression analysis, graphical and tabular methods. It is determined that effective investment of non-state pension funds’ assets provides an increase in the value of assets, which in turn enables participants of non-state pension funds to enhance the quality of life. Involving non-state pension funds in the stock market and their interaction with other entities in this market are illustrated by the investment in bonds example. The market of bonds in Ukraine for 2013-2017 has been analyzed and the tendency towards development has been determined. The possibilities and threats of investment of non-state pension funds’ assets in bonds are substantiated. The approach to determining the impact of factors on the government bond yields, in particular, bonds of domestic state loans and bonds of enterprises has been further developed. This approach, unlike the existing ones, provides for the use of regression analysis and takes into account changes in the environment according to factors (consumer price index and household income for government bonds, the number of enterprises and the discount rate of the National Bank of Ukraine for bonds of enterprises). That is of practical importance and will make it possible to improve the investment strategy of non-state pension fund assets in bonds.