Abstract: A continuous butt welding method using plasma and laser, and a method for fabricating a metal tube using the butt welding method are disclosed. The butt welding method conducts a laser welding and a plasma welding together against an object to be welded, which has a very narrow butt space. In particular, the plasma is prior to the laser so that the object is preheated by the plasma, and then a preform is melted by a laser beam in order to accomplish the major welding. In addition, a metal sheet is bent to have a circular section so that its both ends are faced with each other, and then the faced both ends are welded using the aforementioned butt welding method, thereby fabricating a metal tube. The butt welding method and the metal tube fabricating method mentioned above remarkably improve a welding speed and productivity of metal tube.