A method of forming metal interconnection line for a semiconductor device being capable of forming a plug without voids irrespective of aspect ratios is provided. In one example, the method includes forming a first metal layer on a semiconductor substrate; forming a second metal layer on the first metal layer; forming the plugs by patterning the second metal layer; forming the lower metal interconnection lines by patterning the first metal layer; and forming an interlayer insulating layer having a planarized surface on the substrate to fill gaps between the lower metal lines and between the plugs.