A level shifter and an associated booster driving circuit are provided. The level shifter includes an input stage and an output stage. The input stage includes an input switch, which receives an input signal and is selectively turned on according to the input signal. The output stage outputs a gate driving signal. The gate driving signal is at a low logic level when the input switch is turned on, and is at a high logic level when the input switch is turned off. The logic level of the input signal is substantially the same as the logic level of the gate driving signal.