Multi-walled carbon nanotubes were produced by the decomposition of the acetylene gas with chemical vapor deposition (CVD) method, in which the Fe/SBA-15 mesoporous molecular sieves were prepared in acid solution with the sol-gel method. TEM, high-resolution transmission electron microscope (HRTEM) and SEM were used to observe the Fe/SBA-15 molecular sieve and the as-prepared carbon nanotubes, respectively. And the purified carbon nanotubes was also characterized by Raman spectrum. It's surprising that carbon nanotubes grow from the surface of the Fe/SBA-15 mesoporous molecular sieve. The open, straight carbon nanotubes prepared in this way are well graphitized, and carbon nanotubes array are found somewhere. Furthermore, the diameter of carbon nanotubes becomes large with increasing the Fe content in SBA-15 mesoporous molecular sieve. (c) 2004 Elsevier B.V. All rights reserved.