A semiconductor memory device includes a bit line pre-sense amplifier configured to sense a potential difference between bit line pair and amplify the voltages of the bit line pair based on the sensed potential difference, a bit line main sense amplifier configured to sense a potential difference between the bit line pair and amplify the voltages of the bit line pair to first and second driving voltages based on the sensed potential difference, and a power supplying controller configured to supply the second driving voltage to the bit line pre-sense amplifier and the bit line main sense amplifier.