The purpose of the paper is theoretical justification of theoretical approaches while developing the mechanism of the state investment safety. The tasks of the system of the national economy investment safety are the following: developing investment potential, creating favourable investment climate, forming mechanisms of stable investment activity in the key branches of economy. At the same time, it should also be noted that the complex approach that would allow sufficiently justifying and practically solve the problems of defining indicators, factors of the investment policy and directions of its assurance in realization of the mechanism of investment policy is not sufficiently developed nowadays. This fact determines research topicality. The issue of assuring investment safety is of a special importance in Ukraine that has to assure market economy development, to overcome deformations in the economy structure, to renew products and production apparatus in the industry, to master new kinds of activities. Methodology. The survey is based on the generalization and development of views of the scientific-economic schools, uses approaches of the international agencies and recommendation and normative materials of Ukraine concerning realization of the state investment policy as a totality of interrelated levels and subsystems that allows establishing main functions of the investment safety system. Results of the survey shows that the mechanism of investment safety includes some kinds, forms and methods of organizing investment relations and investment activity, ways of their quantitative determination and establishing interdependence. The concept of investment policy is based on the complex approach and includes the blocks which are locally structured in such way that they allow forming adequate system of its indicators and conducting monitoring of their changes under the influence of the determined factors. The peculiarities and elements of realizing investment safety are determined on the basis of the suggested concept. Criteria assessment of the national economy investment safety should include assessment of: ratio of the national and foreign investments; assurance of the enlarged recreation; level of economy restructuring and re-equipping; level of accumulated resources; level of financing scientific-technical sphere. Low level of investment safety is explained by the lack of wide range of investment objects and imperfection of investment mechanisms, as well as the lack of developed investment market. Practical implications. The suggested conceptual statements concerning formation of the mechanism of realizing investment safety determine unity in the system of economic interests and participants of the investment sphere, as well as solving collisions that appear between them. The priority directions of the state policy in assuring investment safety should become the following: creating favourable macroeconomic and entrepreneurial environment, promoting development of business, protecting owners and strengthening efficiency and transparency of the use of state finances. Value/originality. The suggested conceptual principles of forming efficient mechanism of investment safety give the reason for forming an appropriate system of indicators and allow determining prospects and threads to the investment safety level in the real time.