Abstract
The population of our country decreases approximately 33 million people than the present in 2050, and it becomes approximately 75% of current population, and a ratio 65 years or older becomes approximately 40% from approximately 24%, and it is with an aging society. With this, the yield of taxes of the government decreases, and social security related annual expenditure will increase. On the other hand, most of social infrastructure built for the rapid economic growth period become maintenance, the time when you must update it, and these expenses become enormous, and, at the same time, the outbreak probability of Tokai, the southeast sea, the south seas earthquake will increase. We examine the way of the maintenance of society infrastructure to comprise for a role and the giant earthquake disaster of the social infrastructure in the future in limited time and finance in such society background.