In a lamp driving apparatus, backlight assembly and liquid crystal display device using the same, the lamp driving module is mounted on the substrate and provides lamps with power voltage. Sensors are disposed on the substrate to face the lamps, and detect operation state of the lamps to output sensing signals. Voltage cut-off module is disposed on the substrate and compares the sensing signals with a predetermined reference signal. The voltage cut-off module provides the lamp driving module with voltage cut-off signal when at least one of the sensing signals has an amplitude smaller than the reference signal. The deterioration of the lamps may be prevented, and the life expectancy of lamps except broken lamps may be increased.