A method of fabricating an array substrate for a liquid crystal display device is provided. The method includes steps of forming an amorphous silicon pattern on a substrate; forming a catalyst metal pattern on the amorphous silicon pattern; annealing the amorphous silicon pattern to be converted into a polycrystalline silicon pattern using the catalyst metal pattern as a catalyst; forming a gate insulating layer on the polycrystalline silicon pattern; forming a gate electrode on the gate insulation layer at a position corresponding to the polycrystalline silicon pattern; doping the polycrystalline silicon pattern with impurities using the gate electrode as a doping mask to form an ohmic contact layer and an active layer; forming an interlayer insulating layer having first and second contact holes on the gate electrode, the first and second contact holes exposing portions of the ohmic contact layer; and forming a source electrode and a drain electrode on the interlayer insulating layer, the source electrode and the drain electrode connected to the ohmic contact layer respectively through the first and second contact holes.