The present invention discloses a gain control circuit capable of easing leakage current influence. According to an embodiment of the present invention, the gain control circuit comprises: at least one signal input end for receiving at least one input signal; a signal output end for outputting an output signal; an amplifier coupled between an amplifier input end and the signal output end; and a plurality of gain schemes. Each of the gain schemes is set between the at least one signal input end and the signal output end; and when one of the gain schemes is activated to generate the output signal, the rest gain schemes are inactivated to stop gain production and concurrently discharge leakage currents through their respective grounding paths.