Abstract: This variable damper system for a bridge is installed between a superstructure and a substructure of a bridge and can freely change the damping characteristics so that the inertial force of the superstructure generated in an earthquake will be distributed to the substructure and the vibration will be reduced, and all the functions of a viscous damper/stopper, an energy absorber, and a stopper for preventing excessive response with a shock absorber have been integrated in one unit of this system, so that one unit of this system can perform the same functions as those carried out by a plurality of conventions devices each having an independent function and also a narrow space on the top surface of the substructure of a bridge can be used as it is.