longitudinal direction of the spring guide as a component force in the housing 20 so the whole elastic force of the spring can be concentrated for pushing the housing 20 further the contact structure of the spherical surfaces that generates a sliding movement can increase the operation region of the constant velocity joint that is since there is no interfering factor in behavior of the shaft 10 the bending angle and the sliding distance that the roller kits can slide can be increased since the spring guide 40 of the present invention has the bar shape applying an elastic force to the shaft 10 and the housing 20 by compressing the spring 50 it is possible to prevent bending buckling of the spring 50 which may cause when the spring 50 is compressed and to fix the position of the spring 50 by separating the spring 50 from being separated from the position by a centrifugal force in high speed rotation of the constant velocity joint further the grease filled in the housing 20 is applied to the inside of the through hole 23 too so it is possible to prevent friction when the spring guide 40 slides further the locking portion 41 formed at the spring guide 40 makes the spring guide 40 and the housing 40 easily combined and the diameter restores after it passes through the through hole 23 so the spring guide 40 is prevented from flying due to the elastic force of the spring 50 on the other hand the length of the spring guide 40 according to the present invention is set on the basis of the maximum position to which the shaft 10 can moves outside if the length of the spring guide 40 is set too large the spring.