An array substrate includes a substrate, a buffer layer, a first shielding pattern, a passivation layer, a first semiconductor pattern, a gate insulating layer, a first gate pattern, an interlayer insulating layer, and two first source/drain electrode patterns. A first through hole and a second through hole are arranged on the array substrate. One of the first source/drain electrode patterns is electrically connected to the first semiconductor pattern and the first shielding pattern through the first through hole. The other one of the first source/drain electrode patterns is electrically connected to the first semiconductor pattern through the second through hole and is insulated from the first shielding pattern. The present invention where the array substrate and the method of forming the array substrate are proposed is related to a top-gate design. The driving ability of the TFT driving circuit still improves without increasing the original processes and production costs.