A semiconductor memory device includes a data alignment unit configured to align data, which are sequentially inputted, in response to a data strobe signal, a latching operation control unit configured to receive the data strobe signal, and generate a latching control signal after an interval between a write operation and a next write operation elapses, a data latching unit configured to latch output signals of the data alignment unit in response to the latching control signal, and a data synchronization output unit configured to synchronize output signals of the data latching unit in response to a data input strobe signal, and output the synchronized signals to a plurality of data lines.