To provide a connection structure which can reduce the occupying space necessary for connection, while suppressing the influence of the length unevenness of an outer tube to a pre-load.

An inner tube 7 is inserted to a bolt member 15 projecting from a first member 3, while a second member 1 is fixed to an outer tube 4. An outward flange 7a of the inner tube 7 is inserted between one end face in the axial direction of an elastic body 8 and the first member 3. A washer member 13 provided coaxially on the outer periphery of the bolt member 16 in the condition opposing the other side end face in the axial direction of the elastic body 8 and imparting a pre-load in the axial direction to the elastic body 8 together with the outward flange 7a by fastening a nut member 10 screwed to the bolt member 15, is provided. The outer diameter surface of the elastic member 8 is fixed to the inner diameter surface of the outer tube 4, through a first tube metal fitting 9 pressed in to the inner diameter surface of the outer tube 4. The outer diameters of the washer member 13 and a second tube metal fitting 11 are set smaller than the inner diameter of the outer tube 4, and they are provided at the inner side of the outer tube 4.