A driving apparatus of a light emitting diode (LED) and a driving method thereof are provided. In the driving method, when the driving apparatus performs dimming and a duty cycle of a dimming signal is smaller than a predetermination value, outputting time of driving currents are equally allotted in a period, and a magnitude of each driving current is regulated correspondingly. When the driving apparatus performs dimming and the duty cycle of the dimming signal is equal to or greater than the predetermination value, the driving currents are simultaneously output in the period, and the magnitude of each driving current is regulated according to the dimming signal. Therefore, an audio noise and an electromagnetic interference caused by excessive variation of a sum of the driving currents are suppressed.