Single-walled carbon nanotubes (SWNTs) have been successfully prepared from coal gas by catalytic chemical vapor deposition technique with ferrocene as catalyst. The SWNTs products were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectroscopy. The growth mechanism of the SWNTs derived from coal gas was discussed in terms of the catalyst property and the coal gas composition. The results demonstrate that coal gas is one of the suitable starting carbon sources for making SWNTs by catalytic decomposition method. (C)2004 Elsevier B.V. All rights reserved,