Carbon nanotubes have been synthesized by chemical vapor deposition on graphite foil coated with stainless steel film as catalyst by magnetron sputtering. Annealing in hydrogen was used to convert the stainless steel film to the needed catalyst particles that have a different composition from the initial stainless steel film due to phase segregation during annealing. The catalyst particle size increases with the increase of the initial stainless steel film thickness. The outer diameter of the carbon nanotubes increases dramatically with catalyst particle size, whereas the inner diameter increases slightly first then remains roughly constant at about 7 nm.