An array substrate for an in-plane switching mode liquid crystal display device includes a substrate, a gate line along a first direction on the substrate, a data line along a second direction and crossing the gate line to define a pixel region, a common line on the substrate, a thin film transistor connected to the gate and data lines, a pixel electrode in the pixel region and connected to the thin film transistor, the pixel electrode including horizontal parts along the first direction, and a common electrode in the pixel region and connected to the common line, the common electrode including horizontal portions along the first direction, wherein the pixel electrode and the common electrode are formed on a same layer.