PURPOSE: To prevent the electrolytic corrosion of a shaft by forming the non- conductive layer on an external surface end of a pipe or internal surface of a backup ring, in the area where the conductive backup ring is fitted externally.

CONSTITUTION: An inner layer 2A of a power transmission shaft 1 is formed in filament winding of the roving with conductive fiber, and the outer layer 2B is formed in filament winding of a roving having non-conductive fiber. A yoke 3 is fitted closely into the pipe 2 and a conductive metallic backup ring 4 is fitted externally on the pipe 2. Thus, in the area where the backup ring is mounted, the backup ring is not made in contact directly with the conductive fiber, thus preventing the electrolytic corrosion of the shaft.