Concrete structures constructed in cold region suffer from many cycles of freeze-thaw in Winter. Especially concrete structures which were constructed before 1930s and which did not contain air entrained (AE) agent suffer remarkably from frost damage due to freeze-thawing. Some of them, however, are of good designs and harmonize well with the surrounding environment. So some campaigns to preserve the structures are in progress, for example, in Kamishihoro, Shyari and so on in Hokkaido. Furthermore, the maintenance and management for long term service of these structure is important for efficient public investment. The purpose of this study is basically to :1) Investigate the change in time of concrete arch bridge constructed in cold region 60 years ago by researching at the site and to look up design plan report of that time.2) Analyzing the freeze-thaw cycles of section on member toward direction of depth as an external factor.3) Evaluate the safeness and performance of the structure influenced by change in time by analyzing with finite element method (FEM) and look up design plan report of that time in order to predict remaining serviceable years.