Carbon microcoils (CMCs) and carbon nanocoils (CNCs) were prepared by the catalytic pyrolysis of acetylene using Ni-based or Fe-based catalysts supported on molecular sieves by the catalyzed chemical vapor deposition (CCVD) process. The growth pattern, morphology and structure of the CMCs and CNCs (to be called by a joint name 'carbon coils') were examined in detail. By using a ceramic supporter, the anisotropy of the catalysts could be utilized and carbon coils could be more effectively obtained compared to non-supported alloy catalysts. Furthermore, the morphologies of the carbon coils could be controlled. The Raman spectra indicated that the structures of all these carbon coils were nanocrystalline phases in amorphous networks in spite of the different catalysts and preparation conditions. (C) 2006 Published by Elsevier Ltd.