To prevent a joint collar from coming off and turning without additional processing on a piston rod in a structure for mounting a hydraulic damper onto the body of a vehicle.

In the structure for mounting the hydraulic damper onto the body of a vehicle, mount rubbers 24 and 25 are installed between upper and lower washers 22 and 26 of which positions are regulated by the joint collar 23 inserted through an upper end of the piston rod 12, and the mounting rubbers 24 and 25 are mounted on the body of a vehicle via the the upper washer 26 while being cramped with a nut meshed with a thread portion of the piston rod 12. A part of the lower end at a peripheral direction of the thread portion 28 of the piston rod 12 is crimped by the joint collar 23, and the joint collar 23 is mounted on the piston rod 12.