An array substrate for an LCD device and a manufacturing method thereof. The array substrate includes: a gate line, a gate electrode, a gate pad, and a pixel electrode formed on the substrate; a gate insulation layer formed on the substrate to expose the gate line and the pixel electrode; a source electrode connected to a data line crossing the gate line, a drain electrode facing the source electrode with a channel interposed, a data pad formed at one end of the data line, and a capacitor electrode overlapping portions of the pixel electrode and the gate line; a semiconductor layer constituting the channel between the source electrode and the drain electrode; first, second, third, and fourth contact holes formed in the gate pad, the data pad, the capacitor electrode, and the drain electrode, respectively; and first through fourth contact electrodes formed in the first through fourth contact holes, respectively.