A development of information infrastructure for correspondence using fiber optics cable is planned for the purpose of preventing and managing river disaster in the region of Tokachi riverside. Not only the completion of disaster prevention system but also the regional promotion effects will be brought if the regional information network system making use of the space of tunnel for fiber optics cable is developed. In this study, a questionnaire survey with respect to regional information network is carried out to local residents lived in the region of Tokachi riverside, and the evaluation of regional promotion effects brought by the development of information infrastructure is also carried out. The evaluation method used in this study is Covariance Structure Analysis, and this study clarifies the relationship between the development of information infrastructure and the regional promotion effects. As a result, it is concluded that the development of information infrastructure will bring the regional promotion effects such as the increase of interest in administrative information and regional subjects, the activation of exchanging information, the promotion to use regional information and so on.