Disclosed is a liquid crystal display device having a lamp driving apparatus for preventing lamps from being damaged due to electric current variation among the lamps. A DC/DC converter converts an externally provided DC voltage input into a converted DC voltage signal having a predetermined voltage level. A DC/AC inverter inverts the converted DC voltage signal into an AC voltage signal to supply the inverted AC voltage signal to an input terminal of a lamp. A power controller detects electric current flowing the lamp at an output terminal of the lamp to control the level of the inverted AC voltage signal output from the DC/AC inverter and bypasses a part of electric current applied to the input terminal of the lamp when a level of the detected electric current is higher than a predetermined threshold value. Therefore, when the level of the electric current flowing through the lamp exceeds the predetermined threshold value, the power controller bypasses the part of the electric current supplied to the lamp to the ground, thereby decreasing the amount of the electric current supplied to the lamp and preventing the lamp from being damaged.