An amplifying circuit includes an operational amplifier, a pull-up circuit and a pull-down circuit. The operational amplifier generates a first pull-up signal, a first pull-down signal and an output signal, wherein the phases of the first pull-up signal and the first pull-down signal are out of phase with the output signal. The pull-up circuit includes a first controlling module for outputting a second pull-up signal according to the first pull-up signal, and a first adjusting module for adjusting the output signal according to the second pull-up signal. The pull-down circuit includes a second controlling module for outputting a second pull-down signal according to the first pull-down signal, and a second adjusting module for adjusting the output signal according to the second pull-down signal.
