A method for fabricating an array substrate is disclosed. The method comprises: forming a first oxide semiconductor active layer of a first TFT in a GOA area of a substrate; performing a first annealing process on the first oxide semiconductor active layer at a first temperature; forming a first insulating layer which covers the first oxide semiconductor active layer; performing a second annealing process on the first oxide semiconductor active layer at a second temperature, wherein the second temperature is lower than the first temperature. This improves a forward bias stability of the first TFT and increases the device lifetime.