A pixel array substrate and a liquid crystal display are provided. The liquid crystal display includes the pixel array substrate, an opposite substrate and a liquid crystal layer. The liquid crystal layer is disposed between the pixel array substrate and the opposite substrate. The pixel array substrate has plural pixel electrodes. Each pixel electrode has a first main portion, a second main portion, a plurality of first and second branches. The first main portion is substantially vertically connected to the second main portion and sequentially defines a first quadrant, a second quadrant, a third quadrant and a fourth quadrant. Each first branch is connected to the first main portion and/or the second main portion. The orientation angles of the first branches in the same quadrant are substantially identical. Each second branch is connected to a plurality of the first branches. Each quadrant has at least one of the second branches.