A lamp driving apparatus includes a change rate calculating section, a dimming transforming section and a power supplying section. The change rate calculating section calculates a change rate signal from an image signal corresponding to the image. The dimming transforming section outputs a digital dimming signal and an analog dimming signal, in response to a dimming signal provided from an external device and the change rate signal. The power supplying section provides the lamp with power, in response to a vertical synchronizing signal, the analog dimming signal and the digital dimming signal. Thus, although an instantaneous lamp current is increased, life and characteristics of the lamp will not be adversely influenced, and motion blur of a moving image may be removed.