A gas turbine including a compressor, a combustor and first stage to fourth stage turbine blades and four stage turbine vanes, and a turbine blade cooling system, in which the compressor includes a plurality of rotation members, and the compressor is divided into a front-stage compressor, a middle-stage compressor and a rear-stage compressor in sequence from a farthest position from the combustor, wherein after driving the first stage to the fourth stage turbine blades, a combustion air is discharged to an outside of the gas turbine; the gas turbine comprising: outside paths for inducing fluid from the compressor through the outside of a gas turbine casing; a center shaft path for supplying fluid from the compressor by penetrating the inside of a center shaft of the gas turbine; and inside paths for supplying fluid from the compressor through a connection to the outlet of the compressor, wherein the fluid induced through the outside paths, the center shaft path or the inside paths cools at least part of the turbine blades; and wherein the front-stage compressor, the middle-stage compressor and the rear-stage compressor are respectively provided with inlets of the outside paths, wherein the outside path connected to the front-stage compressor has outlets provided to at least one turbine vane and a combustion air discharge hole cover; wherein the outside path connected to the rear-stage compressor is provided to at least one turbine vane; and wherein the inside paths directly supply fluid from the compressor to at least one turbine vane and at least one turbine blade; and wherein - the outside path connected to the middle-stage compressor has an outlet provided to at least one turbine vane, and the middle-stage compressor is additionally provided with an inlet of the center shaft path, and an outlet of the center shaft path is provided to at least one turbine blade. outside paths for inducing fluid from the compressor through the outside of a gas turbine casing; a center shaft path for supplying fluid from the compressor by penetrating the inside of a center shaft of the gas turbine; and inside paths for supplying fluid from the compressor through a connection to the outlet of the compressor, wherein the fluid induced through the outside paths, the center shaft path or the inside paths cools at least part of the turbine blades; and wherein the front-stage compressor, the middle-stage compressor and the rear-stage compressor are respectively provided with inlets of the outside paths, wherein the outside path connected to the front-stage compressor has outlets provided to at least one turbine vane and a combustion air discharge hole cover; wherein the outside path connected to the rear-stage compressor is provided to at least one turbine vane; and wherein the inside paths directly supply fluid from the compressor to at least one turbine vane and at least one turbine blade; and wherein - the outside path connected to the middle-stage compressor has an outlet provided to at least one turbine vane, and the middle-stage compressor is additionally provided with an inlet of the center shaft path, and an outlet of the center shaft path is provided to at least one turbine blade. - the outside path connected to the middle-stage compressor has an outlet provided to at least one turbine vane, and the middle-stage compressor is additionally provided with an inlet of the center shaft path, and an outlet of the center shaft path is provided to at least one turbine blade.