An array substrate is provided. The array substrate includes a substrate, a light-shielding layer formed on the substrate, a buffer layer formed on the light-shielding layer, a semiconductor layer formed on the buffer layer, a protection layer formed on the semiconductor layer, an insulating layer formed on the protection layer, and an interlayer dielectric layer formed on the protection layer. The substrate includes a source layer, a drain layer and a gate layer disposed thereon. The source layer and the drain layer are formed on the interlayer dielectric layer. The source layer and the drain layer are separately connected to conductor portions on two ends of the semiconductor layer. The insulating layer is disposed between the gate layer and the semiconductor layer. The interlayer dielectric layer is disposed to cover the gate layer and the protection layer. The insulating layer is disposed to cover the semiconductor layer.