A manufacturing method of an array substrate including following steps is provided. A plurality of scan lines are formed on a substrate having a pixel region and a fan-out region. A plurality of data lines are formed. A plurality of transistors are formed and respectively electrically connected to the corresponding scan lines and data lines. A plurality of common electrodes are formed. A plurality of pixel electrodes are formed and respectively electrically connected to the corresponding transistors. A plurality of first fan-out lines, second fan-out lines, and third fan-out lines are formed in the fan-out region. Each of the third fan-out lines includes a transparent conductive layer and an auxiliary conductive layer located on and contacting the transparent conductive layer. The third fan-out lines and the common electrodes are formed by the same photomask.