A shaft structure installed in a shaft capable of making a power-transmission, the shaft structure including: a male component having a plurality of male splines formed on an outer peripheral part thereof; and a female component having a plurality of female splines formed on an inner peripheral part thereof, the inner peripheral part configured to allow the outer peripheral part of the male component to be engaged therein so that the male component and the female component can be slidably fitted with respect to each other in an axial direction thereby making up said shaft structure, wherein the outer peripheral part of the male component and the inner peripheral part of the female component have a fabric impregnated with rubber or resin interposed therebetween.