A blade coupling structure and a turbine system having the same securely couple a blade to a rotor disk. The blade coupling structure includes a root elastic member disposed between a root end of a blade root of the blade and an inner end of a coupling slot formed in the rotor disk; and a wedge member having a wedge body fitted between the root elastic member and the inner end of the coupling slot. The wedge member and the root elastic member press each other and press the root end so that the blade root is fixedly coupled to the coupling slot. A flat portion of the wedge member contacts the root elastic member, and an inclined portion of the wedge member facilitates the fitting of the wedge body. A wedge passage is formed in non-contact regions of the wedge body and passes a cooling fluid to the blade.