An array substrate for an IPS mode LCD device includes a gate line in a first direction on a substrate and a data line in a second direction over the substrate; a metal and a common lines in the second direction on the substrate and includes a plurality of first and second protruding portions in the first direction, respectively; a TFT connected to the gate and data lines; an insulating layer over the metal and common lines; a common electrode over the insulating layer and including a first common portion in the second direction and a plurality of second common portions in the first direction; and a pixel electrode over the insulating layer and including a first pixel portion in the second direction and a plurality of second pixel portions in the first direction, wherein the plurality of second common and pixel portions are alternately arranged.