A thin film transistor array of a horizontal electronic field applying type enhances brightness. The thin film transistor array includes a gate line and common line separated from the gate line; a data line crossing with the gate line to define pixel region and insulated from the gate line by a gate insulating film; a TFT connected to the gate line and the data line in the pixel region; a pixel electrode on a passivation film overlapping with the common line in the pixel region and connected to the TFT; and a common electrode on the passivation film opposed to the pixel electrode in the pixel region and connected to the common line, wherein the width of the pixel electrode at the overlapping portion between the common line and the pixel electrode is narrower than the width of the common line, and the edge of one side of the pixel electrode adjacent to the common electrode is formed on the inside of the edge of one side of the common line adjacent to the common electrode.