A semiconductor memory device comprises a write column select line or read column select line for shielding a signal line. The semiconductor memory device may include a signal line, a read column select line, and a write column select line. The signal line may transmit an operation signal related to the operation of the semiconductor memory device. The read column select line may transmit a read column select signal, which may control transfer of a data signal of a bit line to a data line. The write column select line may transmit a write column select signal, which may control transfer of the data signal of the data line to the bit line. One of the read column select line and the write column select line to transmit a deactivated column select signal among the read column select signal and the write column select signal, may be maintained at a predetermined logic level and may shield the signal line.