The activity and stability of Ni/SiO2 catalyst for the decomposition of methane at different temperature were investigated and the types of deposited carbon were also monitored. The catalyst was prepared by impregnation method and characterized by XRD, TG, SEM, Raman, TPH and TPO techniques. The dependence of the morphology, structure, and amount of deposited carbon over the used catalyst on the reaction temperature was studied. The results suggested that the Ni/SiO2 catalyst showed the best initial catalytic activity at 700 degrees C for the catalytic decomposition of methane, where the carbon whisker was the finest and densest, and the proportion of the well-ordered graphic was enhanced with increased reaction temperature. The largest amount of carbon deposition was observed at 550 degrees C used catalyst, and at this reaction temperature the Ni/SiO2 catalyst showed relatively the highest stability. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.