A semiconductor memory device and a sense amplifier thereof are provided. The semiconductor memory device includes a memory cell array and a plurality of sense amplifiers. The memory cell array includes a memory cell array block having a plurality of memory cells. Each of the plurality of sense amplifiers is configured to apply, based on a restore signal, a first voltage to a corresponding bit line to restore a first data value in a selected memory cell of the plurality of memory cells if a read value in the selected memory cell is the first data value and apply a second voltage based on the restore signal to the corresponding bit line to prevent a second data value from being restored in the selected memory cell if the read value in the selected memory cell is the second data value.