Abstract: Methods for choosing the best multiple regression models in the sustainable development of the region's economic system are considered and the forecast of the processes of economic dynamics of the built models will be analyzed. Econometric modelling of sustainable development of economic systems of the region uses multivariate regression analysis and the method of least squares. These methods will help to identify the factors influencing the sustainable development of the economic system and assess their impact. In addition, when analyzing the sustainable development of the economic systems of the region, the degree of interconnections of influencing factors was calculated using the method of statistical grouping. These methods determine the prospects for the sustainable development of economic systems. Several econometric models have been developed for forecasting GRP using data that fully reflect the dynamics of sustainable development of economic system of the region. The relationship between investment, capital and labour force, affecting the sustainable development of economic system of the region, has been studied. The results of the work can be applied by scientists and practitioners interested in issues for predicting the sustainable development of economic systems in the region using econometric models. The forecasts obtained using these models are quite reliable from the point of view of statistical estimates. Based on this, the Cobb-Douglas three-factor production function describes well the sustainable development of economic system of the region. First of all, for the sustainable development of the economic systems of the region, it is necessary, taking into account the specific features of the region, to develop a map of the GRP spheres, on which slowly developing, rapidly developing and spheres in need of development emerge.