A thin film transistor array comprising a plurality of common lines for providing the storage capacitance of pixels is provided. In particular, each of the common lines comprises a plurality of branches. Wherein, the common line and the branches thereof, and the pixel electrode constitute the storage capacitor. The branches are disposed at pixels where the luminance quality is bad. Therefore, the storage capacitance of the pixels can be enhanced without altering the aperture ratio of the pixels. Accordingly, the performance of the liquid crystal display panel can be improved.