A nonvolatile memory device includes cell strings commonly connected between bitlines and a source line where the cell strings are grouped into memory blocks. During a precharge period, channels of the cell strings of a selected memory block are precharged by applying a gate induced drain leakage (GIDL) on voltage to gates of GIDL transistors included in the cell strings of the selected memory block where the GIDL on voltage has a voltage level to induce GIDL. During the precharge period, precharge of channels of the cell strings of an unselected memory block are prevented by controlling a gate voltage of GIDL transistors included in the cell strings of the unselected memory block to prevent the GIDL. During a program execution period after the precharge period, memory cells of the selected memory block connected to a selected wordline are programmed by applying a program voltage to the selected wordline.