Car-Parrinello molecular dynamics simulations were performed to study the dissociation of oxygen molecule on the Pt(1 1 1) surface at 350 K. The results show oxygen dissociation is a step-by-step process. The dissociated oxygen atoms can form fcc-fcc or fcc-hcp adsorption structure on the Pt(1 1 1) surface, which is consistent with the results of previous experiments. The Kohn-Sham energy evolutions indicate that the hcp-hcp adsorption structure possesses relatively high energy, and would transform into an fcc-hcp adsorption structure with low energy barrier. This study provides important information in understanding the oxygen dissociation dynamics at the atomic level. (C) 2014 Elsevier B.V. All rights reserved.