Biogas reforming for hydrogen production over mesoporous Ni2xCe1-xO2 catalysts were proposed in this study. Mesoporous Ni2xCe1-xO2 (x = 0.05, 0.13, 0.2) was prepared by a reverse precipitation method. The effects of nickel content were investigated in physicochemical properties and catalytic activities. All of the catalysts were reduced with 10% H-2/Ar at 600 degrees C before reactions, the reduced catalysts were found to be active for both dry and steam reforming of methane (CH4:CO2:H2O = 3:1:2) to produce hydrogen and syngas. The studies were firstly carried out by temperature program reaction from 400 degrees C to 900 degrees C to verify the activity of temperature dependency. The long-term stability analysis was also studied at 700 degrees C for 24 h. Commercial catalyst (R67) was also employed for a comparative purpose. Current results by the proposed catalysts revealed the higher H-2/CO ratio and the lower H-2/CO2 ratio than that by using R67 in the steam reforming reaction from temperature range 500 degrees C-900 degrees C. It was also observed that methane conversion increased with increasing nickel content in all tests. In long term activity tests, Ni0.4Ce0.8O2 showed excellent activities as same as R67 for biogas steam reforming. After 24 h, deactivations of Ni0.1Ce0.95O2, Ni0.26Ce0.87O2 and Ni0.4Ce0.8O2 were 84.6%, 0.5% and 2%, respectively. For this reason, mesoporous Ni0.26Ce0.87O2 and Ni0.4Ce0.8O2 were more suitable for biogas steam reforming reactions. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.