A data receiving device of a memory device comprises a first pre-amplifier configured to receive previous data, a first reference voltage, and input data, and to output differential signals by comparing the input data with the first reference voltage in response to a clock, when the first pre-amplifier is selected in response to the previous data, a second pre-amplifier configured to receive inverted previous data, a second reference voltage, different from the first reference voltage, and the input data, and outputting a common signal in response to the clock, when the second pre-amplifier is unselected in response to the previous data; and an amplifier configured to receive the differential signals and the common signal, and to latch the input data by amplifying the differential signals.