We investigate the stable structures and magnetic properties of Fe-filled single-walled carbon nanotubes (SWNTs) on Ni(111) using first principle calculations. For the two different initial positions of Fe atom inside the nanotube, we find stable geometries and electronic states for the SWNT on Ni(111). When the Fe wire is near the Ni surface, SWNT transforms into arch-like structure. We propose the possibility that the C-C bonds of carbon nanotube are broken by Fe wire and Ni surface.