A cooling structure for a trailing edge of a turbine blade is provided. The cooling structure for the trailing edge of the turbine blade comprising an airfoil shaped blade part including a leading edge, a trailing edge, a pressure surface and a suction surface connecting the leading edge and the trailing edge, and a cavity channel formed in the blade part and through which a cooling fluid flows, the cooling structure including slots and lands arranged alternately on the trailing edge along a span direction of the pressure surface by cutting a portion of the pressure surface, the slots communicating with the cavity channel and defined by adjacent lands where the pressure surface remains, wherein a pin-fin structure is disposed in the cavity channel on an upstream side of the slot, and wherein the cooling fluid is introduced through a micro-channel formed inside the pin-fin structure and is discharged through film cooling holes formed in the pressure surface.