An input/output circuit for a semiconductor memory device, including a data output circuit configured to buffer output data in the semiconductor memory device in response to an input/output enable signal to output the buffered output data to an input/output signal line, a data input circuit configured to receive input data from the input/output signal line and buffer the input data to transfer the buffered input data to the semiconductor memory device, and a load controller configured to control a load on the input/output signal line in response to the input/output enable signal.