A semiconductor memory device includes a block decoder configured to output block selection signals for selecting memory blocks in response to a row address signal, a first memory block including a first drain select line, a first source select line, and a first word line group including a plurality of first word lines disposed between the first drain select line and the first source select line, the first memory block disposed between the block decoder and a first switching group, the first switching group configured to transmit first operating voltages to the first memory block in response to a first block selection signal among the block selection signals, and a first block word line configured to transmit the first block selection signal to the first switching group and disposed over the first memory block to avoid overlapping with the first word line group.