Density functional theory calculations are presented for adsorption and dissociation of CH(4) on clean and oxygen atom pre-adsorbed metal surfaces (Cu, Ag, Au, Ni, Pd, Pt, Ru, Rh, Os, Ir, and Mo). The total energy change and the activation barrier have been calculated for the direct and the oxygen-assisted cleavage of the C H bonds. Our results indicate that pre-adsorbed oxygen promotes the CH(4) dissociation process on IB group metal surfaces, but inhibits the dissociation process on transition metal surfaces. A good Bronsted-Evans-Polanyi correlation for CH(4) dissociation on clean and atomic oxygen pre-adsorbed metal surfaces is found, which is helpful to reveal the nature of CH(4) dissociation. From the analysis of activation barrier, we expect our work can provide a clear understanding of the nature of CH(4) dissociation. (C) 2011 Elsevier Inc. All rights reserved.