Abstract
Social and Economic Infrastructure Investments in Japan have been steadily accumulated, especially since post World War R. They may have not been brought up to the extent that European countries or USA have, but it is certainly said that such infrastructure development has contributed to build up national strength and to enrich our sociocultural activities as well as our life. Today our country is facing the society of high age which is not comparable to the other countries in the world and also the domestic industries are entering into the structually turning point. Taking these conditions into due recognition, it would be an essential process to review our past improvemnt of social and economic infrastructure so far made and its basic system in order to deal whit their future development. This paper was prepared in mind that the basic idea for future infrastructure could be based on this study in one sense. Therefore, the basic concept of infrastructure development, its changes and related legislative arrangements were compiled and then actual projects as concrete measures of infrastructure development in and out of Japan whit the fundamental needs, background, examples and the recent trends were introduced. Inaddition, this touched about the direction of new project development in Japan from now.
