The structural and electronic properties of Pt monolayer adsorption on both PbO and TiO2 terminations of PbTiO3(100) surface have been investigated by first-principles projector-augmented wave calculations with slab models. It is found that Pt monolayer prefers to bind on PbO site of PbO termination and on O site of TiO2 termination. The main impetus for the stability of these preferred binding sites is the close proximity of Pt atoms to O atoms. In addition, strong interaction between Pt atom and the first layer O atom is observed and the hybridization between Pt 5d orbital and the O 2p orbital is found. Moreover, the coordination number dominates the position of the DOS curve while the hybridization mainly influences the shape of the DOS and results in new peaks. (C) 2009 Elsevier B.V. All rights reserved.