Carbon nanofibres (CNFs) were prepared by catalytic decomposition of gaseous ethylene on NiCu/H-ZSM-5. They were characterized by XRD and TEM techniques. Dehydrogenation characteristics of LiAlH4 admixed with CNFs and Vulcan XC72R were studied and compared with that of pure lithium aluminium hydride. The results show that CNFs have prominent effect on the dehydrogenation properties of LiAlH4. On the basis of the dehydrogenation characteristics, a possible mechanism for the dehydriding of LiAlH4 upon addition of carbon materials has been considered. © 2007 International Association for Hydrogen Energy.