A source driving circuit adapted to drive a display panel is provided herein. The source driving circuit includes a first output buffer and a second output buffer responsible for enhancing signals with different polarities respectively. As for the first output buffer, the first output buffer includes a first differential input stage, a first output stage and a second output stage. The first output stage includes a first level adjustment circuit and a first self-bias providing circuit. The first level adjustment circuit provides a first level voltage according to input signals received by the first differential input stage, such that the second output stage thereby provides a first charge current and a second charge current to output a first output signal based on the first level voltage. The first self-bias providing circuit provides a first biased voltage associated with one input signal to control the first level adjustment circuit to operate.