Ceria oxide (CeO2) nanofibers with diameters of 241-253 nm were produced via the electrospinning method. They were then applied as new support materials for silver nanoparticles and their effectiveness as diesel soot oxidation catalysts was examined. The crystal structure of the Ag was confirmed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HR-TEM), and energy dispersive spectroscopy (EDS). The diesel soot oxidation experiment was performed using a mixture of carbon black and the fabricated catalyst. In the tight contact and loose contact modes, the highest temperatures of both the CeO2-fiber-supported Ag catalysts (Ag/CeO2) calcined at 500 degrees C and the CeO2 fibers calcined at 500 degrees C were shifted to a lower temperature range, compared with JRC-CEO-3 (a commercial catalyst). In addition, the activation energy also showed similar behavior. Thus, the fibrous CeO2 and Ag/CeO2 have been shown to be effective and promising catalysts for soot oxidation. (C) 2015 Elsevier B.V. All rights reserved.