Abstract: Carbon nanotubes were modified by FeSO4-H2O2 and iron hydroxides were adsorbed on the walls of carbon nanotubes simultaneously. These precursors were treated at 723K for 2h under hydrogen, nitrogen and air atmosphere to prepare carbon nanotube-supported γ-Fe2O3 catalyst, a γ-Fe2O3 and α-Fe2O3 compound catalyst and amorphous Fe2O3 catalyst, respectively. The catalysts were characterized by X-ray diffraction, transmission electron microscopy and TG-DSC. The catalytic activity was estimated by the dehydrogenation of ethylbenzene to styrene in a fixed bed reactor with a continuous flow system at atmospheric pressure. Results show that the effect of thermal treatment conditions on the catalytic performance activity for the dehydrogenation of ethylbenzene is very sensitive. Novel carbon nanotube-supported crystalline Fe2O3 catalysts were found to have a high activity and selectivity for ethylbenzene dehydrogenation.