Complexity of economic systems modeling for ef-ficiency assessment of their functioning and elabora-tion of development forecasts can be explained by a number of factors. One of them is heterogeneity of economic systems, significant dependence of their structure and principles of key elements interaction on the management level, industry membership, the scope of system work. Vector and development dynamics of socio-economic system are determined, on the one hand, by internal potential of its elements , each im-plements its own development trajectory on the micro-level, and on the other hand – by opportunities of the external environment which is characterized by a com-plex mix of macroeconomic, political, social, technolo-gical and natural factors. Analysis of the existing development methods of economic systems models at different levels allows marking out several modeling technologies among which the most promising from the point of view of application in real management practice can be considered the technology of imitation modeling based, in turn, on three methodological approaches. For the solution of a modeling problem of regional socio-economic system combined approach application appears to be the most effective within which external macroprocesses are modeled by means of system dynamics, and internal – socio-economic processes are formalized by agent-based modeling methods.