An exemplary method for fabricating a TFT array substrate includes providing an insulating substrate (201); coating a gate metal layer (202) on the substrate; forming a plurality of gate electrodes (212) using a first photo-mask process; forming a gate insulating layer (203), a semiconducting layer (205), and a source/drain metal layer (206) on the substrate having the gate electrodes; forming a plurality of source electrodes (217) and a plurality of drain electrodes (218) using a second photo-mask process; forming a passivation material layer (209) and a photo resist layer on the gate insulating layer, the source electrodes and the drain electrodes; forming a passivation layer (219) and the photo resist pattern (234) using a third photo-mask process; forming a transparent conductive metal layer (204) on the photo resist pattern, the drain electrode and the gate insulating layer; and forming a pixel electrode (214) through removing the photo resist pattern.