A gas turbine includes a compressor rotor having a plurality of compressor rotor disks installed therein; a turbine rotor having a plurality of turbine rotor disks installed therein; a connection part connecting the compressor rotor and the turbine rotor to each other; a tie rod extended through the central axes of the plurality of compressor rotor disks and the central axes of the plurality of turbine rotor disks; and a clamping member forced onto the tie rod in the an axial direction of the tie rod so as to be rotated with the tie rod, and relatively rotated with respect to the an inner circumferential surface of the connection part, thereby damping vibration and shock.