A level shifter for a source driver of a liquid crystal display is provided. The level shifter includes: an input stage for generating a signal with a voltage of between a positive input source voltage and a negative input source voltage according to an input logic; a middle stage for generating a first logic signal and a second logic signal according to the signal; and an output stage, for generating a first output signal with a voltage of between a first positive output source voltage and a first negative output source voltage at a first output terminal or a second output signal with a voltage of between a second positive output source voltage and a second negative output source voltage at a second output terminal according to the first logic signal and the second logic signal.