A liquid crystal display device includes a timing controller generating a voltage compensation control pulse and a gate control signal, a voltage compensation signal generator generating a voltage compensation signal, the voltage level of which is gradually reduced during one frame period, in response to the voltage compensation control pulse, a power unit outputting a gate-on voltage to a plurality of gate lines by gradually increasing the level of the gate-on voltage in response to the voltage compensation signal, and a gate driver sequentially supplying the gate-on voltage to the plurality of gate lines in response to the gate control signal.