A driving circuit of a display panel and driving method thereof are provided. The driving circuit of the display panel has a capacitor, a first, second, third, fourth, fifth, and sixth thin film transistor, a reset thin film transistor, and an output thin film transistor. A sixth and seventh drain electrode, and an eighth gate electrode are connected to a signal output line, a sixth source electrode is configured to receive a fourth power source signal, an eighth is configured to receive a fifth power source signal, and an eighth drain electrode is connected to a sixth gate electrode.