A driver circuit of an AMOLED (active matrix organic light emitting diode) with gamma correction includes a voltage selector, an operational amplifier, a MOS transistor, and a resistive element. The voltage selector selects one of a plurality of gamma voltages. The operational amplifier receives the selected gamma voltage and a feedback signal to generate a control signal. The MOS transistor provides the feedback signal and conducts a current associated with a current type pixel circuit in response to the control signal. The resistive element is coupled to a first voltage end and an inverted input end of the operational amplifier for determining the current with the selected gamma voltage.