We report SnO2-embedded worm-like carbon nitride nanofibers (SnO2-CNx) as support for Pt nanoparticles, which show a significant enhancement in catalytic activity for the oxygen reduction reaction (ORR). Transmission electron microscopy (TEM) results show that Pt nanoparticles are uniformly distributed on the surface of SnO2-CNx. A strong interaction between metal nanoparticles and support in Pt/SnO2-CNx was confirmed by X-ray photoelectron spectroscopy, which could change the electronic structure of Pt atoms. The synthesized Pt/SnO2-CNx. exhibits superior catalytic activity and stability in ORR. The activity of commercial Pt/C lost about 16.9% and Pt/C-CNx 11.8% after 5000 electrochemical cycles. In contract, the Pt/SnO2-CNx only lost less than 5% in ORR activity. The significantly improved activity and stability of Pt/SnO2-CNx are resulted from the modification of Pt electronic structure and strong interactions between Pt nanopartiles and SnO2-CNx. (C) 2014 Elsevier Ltd. All rights reserved.