A multi-port memory device improves efficiency of a global data drive by controlling the global data bus to transmit data in a predetermined range. The multi-port memory device includes a global data bus; transmitters and receivers; a termination unit for controlling the global data bus to transmit the data in a range between a first voltage and a second voltage in response to an active mode signal; and a voltage generator for generating the first and the second voltages. The first voltage is higher than a ground voltage and the second voltage is lower than a power supply voltage.