Source driving amplifier of LCD

The present invention is a source driving amplifier of LCD, which comprises a first input circuit which can be switched into an NMOS differential amplifying circuit or bias circuit by a polarity switching signal; and a second input circuit which can be switched into a PMOS differential amplifying circuit or bias circuit by a polarity switching signal, wherein the output of the first output circuit switched into the NMOS differential amplifying circuit pushes the PMOS transistor of the output transistor pair as the source-out amplified output stage, and the current provided by the NMOS transistor of the output transistor pair is provided for voltage-biasing. The output of the second output circuit switched into the PMOS differential amplifying circuit pushes the NMOS transistor of the output transistor pair as the sink-in amplified output stage, and the current provided by the PMOS transistor of the output transistor pair is provided for voltage-biasing. Thus, the DC offset problem can be effectively solved, and it can be used in the dot-inversion and row-inversion system without resetting the electrical potential.