A semiconductor memory device includes a memory block configured to store a data inputted/outputted through a data transfer line, a data output block configured to output the data loaded on the data transfer line in response to a source clock, wherein the data output block is controlled to be coupled with the data transfer line in response to a write operation signal, a write operation signal generation block configured to generate the write operation signal in response to an operation selection signal and a reference clock lagging behind the source clock by a set time, and a data input block configured to load the data on the data transfer line in response to the write operation signal.