A multi-port memory device includes a plurality of serial I/O data pads; a plurality of parallel I/O data pads; a plurality of first ports for performing a 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 first ports via a plurality of first data buses; and a second port for performing a parallel I/O data communication with the external devices through the parallel I/O data pads and a serial I/O data communication with the first ports via a plurality of second data buses, during a test mode.