An exemplary pixel circuit includes an organic light emitting diode (OLED), a storage capacitance, a driving transistor and first through fourth switching transistors. The driving transistor is for generating a pixel current according to a charge amount stored on the storage capacitance to drive the OLED at a predetermined luminance. The on/off states of the first through fourth transistors are controlled by the same control signal. By means of particular electrical connection relationships of the first through fourth transistors in the pixel circuit, the pixel current flowing through the OLED is irrelevant to the power supply voltage and the threshold voltage of the driving transistor but is increased along with the increase of a cross-voltage of the OLED resulting from long-term use. The present invention also provides an active matrix OLED display using the above-mentioned pixel circuit and a driving method for the pixel circuit.