A nonvolatile memory device includes a first memory block including a plurality of cell transistors interconnected with a plurality of ground selection lines, a plurality of word lines, and a plurality of string selection lines, which are stacked in a direction perpendicular to a substrate, a block selecting circuit that is connected with the plurality of ground selection lines, the plurality of word lines, and the plurality of string selection lines, and provides corresponding driving voltages to the plurality of ground selection lines, the plurality of word lines, and the plurality of string selection lines in response to a block selection signal, respectively, and a block unselecting circuit that is connected only with specific string selection lines of the plurality of string selection lines, and provides an off-voltage only to the specific string selection lines in response to a block un-selection signal.