An image display system is provided. The image display system includes a level shifter including a first voltage adjusting circuit and a second voltage adjusting circuit. The first voltage adjusting circuit adjusting the voltage of an input signal, includes a small signal input terminal receiving the input signal and a differential output terminal outputting a pair of differential signals. The available voltage ranges of the differential signals are larger than that of the input signal. The second voltage adjusting circuit, coupled to the first voltage adjusting circuit, includes a first input terminal and a second input terminal respectively receiving the pair of differential signals. The second adjusting circuit adjusts the voltage of the differential signals and generates an output signal. The available voltage range of the output signal is larger than that of the differential signals.