A semiconductor memory device includes: a plurality of page buffers disposed on a substrate; and a plurality of pads exposed to one surface of a dielectric layer covering the page buffers, and coupled to the respective page buffers. The substrate comprises a plurality of high voltage regions and a plurality of low voltage regions which are alternately disposed in a second direction crossing a first direction. Each of the plurality of page buffers comprises a sensing unit and a bit line select transistor coupled between the sensing unit and the one of the plurality of pads. The bit line select transistors of the plurality of page buffers are disposed in the plurality of high voltage regions, and the plurality of pads are distributed and disposed in a plurality of pad regions which correspond to the high voltage regions and are spaced apart from each other in the second direction.