Abstract: In a boot for a universal joint in which a fitting portion is installed at one end side in an axial direction of a bellows portion on an outer ring portion of the universal joint by the clamp and a relief portion is provided between the bellows portion and the fitting portion on purpose to lower interference between each of the bellows and to relieve a contact of the bellows portion against the shaft in the case when being bent at a sharp angle. This prevents the relief portion from interfering with the tightly clamping portion of the clamp. The relief portion is designed to be arranged apart from the clamp by providing the spacer portion with the predetermined length in the axial direction between the fitting portion and the relief portion.