Single-wall carbon nanotubes (SWNTs) were mass-produced by a newly developed DC are plasma jet method for the evaporation of a metal-doped carbon anode. The production rate of the cottonlike soot was significantly higher than that by conventional DC are discharge evaporation, and the highest yield was 1.24 g/min. Investigations by scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy indicated that more than 50% of the cottonlike carbon soot was composed of fibrous bundles of SWNTs. Through analysis of the breathing modes in the Raman spectra of the cottonlike soot, the diameter of each SWNT was determined to range from 1.28 to 1.52 nm.