A pixel array substrate includes a pixel region and a circuit region adjacent to the pixel region. A plurality of display pixel units are disposed in the pixel region and a plurality of dummy pixel units are disposed in the circuit region. Each of the dummy pixel units includes a data line, a scan line, a plurality of switching elements and a plurality of pixel electrodes. The switching elements are electrically connected to the scan line and data line. The pixel electrodes are electrically connected to the switching elements. Particularly, electrostatic currents in the pixel region can be dissipated by the dummy pixel units in the circuit region. The dummy pixel units preserve the continuity of electricity in the pixel array substrate and function as an inner short ring. Therefore, the area of the circuit region on the pixel array substrate is larger.