A pixel structure including an active device and a pixel electrode is provided. The pixel electrode is electrically connected with the active device and has a plurality of alignment domains. Each of the alignment domains of the pixel electrode has one group of alignment slits parallel with one another, wherein each group of the alignment slits includes a plurality of first alignment slits with a first length and the first alignment slits are majority of each group of the alignment slits. At least one group of the alignment slits includes at least a second alignment slit with a second length longer than the first length of the first alignment slits.