Information systems that imply using mathematical model and enable estimating and forecasting an effect of various factors on the results of social and economic processes may become an effective instrument of comprehensive assessment of territorial development. The present paper considers the elaboration of a mathematical model intended for assessing a region’s social and economic state. Elaboration of an approach to assessment of the dynamics of territorial development is considered in this work as well. Based on the statistical research, values of a number of economical, social and ecological indicators were obtained, which play a significant part in assessing the state of a region. The authors suggest an approach to defining an optimal development pathway in case when long-term plans are already formulated.