Based on the constellation of various approaches to the interpretation of the concept of "diversification", the author's understanding of it is formulated, the main elements of the diversification of the activities of a trading enterprise are identified, and the logic of the relationship of objects, processes and results that make up the content of the studied economic category is established, which is visualized in a logical and meaningful a scheme for diversifying the activities of a trading enterprise in the context of regional and sectoral development of the economy. A process-situational approach to the diversification of the activities of a trading enterprise is proposed, the essence of which is the integration of the features of the regional-sectoral economy, as a situational base, and the diversification of the activities of a trading enterprise, as a process. The use of this approach ensures the synergy of the features of the regional-industrial economy and the architectonics of the process of diversifying the activities of a trading enterprise. A scientific and methodological approach to determining the economic feasibility of diversifying the activities of a retail enterprise is proposed, the use of which helps to increase the efficiency of management decisions when planning the diversification of a trading enterprise in the turbulent conditions of the development of a regional sectoral economy. The scientific and practical approach to identifying the level of efficiency of diversification of the types of activities of trading enterprises has been improved, the constitutive basis of which is the calculation of the integral indicator of the effectiveness of diversification of the types of activities of a trading enterprise, including the indicator of return on total resources, the indicator of profitability of total resources, the indicator of profitability of total resources.