FRP are getting more generally known as a viable alternative to conventional steel reinforcement and has been widely accepted as a convenient material for upgrading existing civil infrastructures. Japan has been a leading country in terms of the number of practical applications and the amount of FRP composites (or continuous fiber reinforcement) used for infrastructures since later 1980s. However, Japanese material manufacturers, constructors, and research units are confronting a challenge how to make FRP composites play a leading role for building up a sustainable infrastructure system. This paper provides a state-of-the-art review on the use of FRP composites for the infrastructures in Japan. The contents include: development and markets of FRP -composites, development of codes standard applications of FRP, and current barriers for further uptake of FRP. Moreover this paper outlooks the future potential roles of FRP composites as the sustainability becomes a major concern for our infrastructure system, which calls the need of advanced construction materials having effective cost, long life-span, less maintenance, less environmental impact, innovative functions, and easiness for the purpose of managing social assets. Efforts are suggested 10 Put into verifying the overall advantages of FRP related to all these aspects.