The book explores theoretical positions and methodological approaches to modeling of information interaction of participants of regional ISC. The analysis of modern models of information space ISC and revealed the role of information infrastructure in the effective functioning of participants of regional ISC. Methodical recommendations for assessing the economic efficiency and effectiveness of the network information system have been developed, methods and organizational methods for introducing the network information system into the information structure of the regional ISC. have been proposed. The concept of a unified information system of regional ISC on the basis of a comprehensive analysis of the integration of information flows , the possibilities of using the concept as a mechanism for the formation of communication relationships between participants in investment and construction activities are investigated , the Strategy for Reducing Transaction Costs