A novel process was introduced in this paper for the diameter-controlling synthesis of carbon nanofibers (CNFs) in the ethanol flames. The carbon nanofibers were grown oil a nanocrystalline Fe layer, which was electro-deposited on a substrate using periodic reverse (P.R.) pulse plating. It Was found that the quality of the plating nanocrystalline and the corresponding carbon nanofibers wits related with two plating parameters: output pulse frequency (f) and duty cycle (r). In addition to that the straight and helical carbon nanofibers were selectively synthesized by addition of different additives in plating bath. In this paper, the base-growth mechanism of carbon nanofibers was clearly discussed. (C) 2008 Elsevier Ltd. All rights reserved.