A multi-port memory device includes a plurality of serial I/O data pads for providing a serial input/output (I/O) data communication; a plurality of ports for performing the serial I/O data communication with external devices through the serial I/O data pads; a plurality of banks for performing a parallel I/O data communication with the ports; a plurality of first data buses for transferring first signals from the ports to the banks; a plurality of second data buses for transferring second signals from the banks to the ports; and a switching unit for connecting the first data buses with the second data buses in response to a control signal.