Purpose. To create an algorithm of the system of preparation and decision-making of management of structural changes in the system of formation of economy of sustainable development and mathematical formalization for its block of an efficiency estimation of a choice of strategic administrative decision set and to propose a systematic approach to the analysis of trends in structural changes towards the introduction of a sustainable economy. Methodology. The set of general and special methods of cognition was used for scientific research. The method of comparison and scientific analysis was used to develop the algorithm of the system of preparation and decision-making of structural change management in the system of formation of the economy of sustainable development. The method of mathematical formalization was used to develop a mathematical model for selecting the most effective solutions using the specified algorithm. The method of economic modeling is used for the analysis of the indicative approach to decision-making of a systemic nature and the choice of the integral value of the resulting index. The method of comparative analysis, quantitative and qualitative comparison is used for analyzing the existing trends in economic indicators and identifying, when using them, trends in structural changes for the implementation of a sustainable economy. Findings. An algorithm for the system of preparation and decision-making for managing structural changes for the formation of an economy of sustainable development and a mathematical algorithm for the implementation of the block for assessing the effectiveness of choosing a set of strategic management decisions of the specified algorithm have been developed. The analysis of trends in structural changes for the implementation of the concept of a sustainable economy using a systematic approach has been conducted. A significant unevenness of the structure of financial resources aimed at the implementation of the Development Strategy in 20212023 in the regions of Ukraine has been revealed. Originality. For the first time, an algorithm and a mathematical model for evaluating the effectiveness of management decisions for the management of structural changes in the system of sustainable development economy have been proposed. The use of the forecast of dynamic change in indicators and factors of influence on them for development of effective management strategy is improved. For the first time, it has been proposed to use not indicators of achieving a particular goal, but an integral indicator of a complex systemic achievement of a result to determine the achievement of a certain level of sustainable development of a country, Practical value. The developed algorithm and mathematical approach can be used for scientific research and practical tasks of finding effective management decisions. Since a comprehensive systemic analysis of indicators for all sustainable development goals requires significant computing resources, for operational analysis it is proposed to use indicators that are not included in the main group of indicators determined by the adopted methods. For a practical example of an operational indicative approach, the analysis and forecast of the dynamics of changes in the populations income were used including the available average monthly income, the structure of the populations income, the structure of expenses and savings, and others applying the time series method and taking into account non-random influences.