This study investigated the influence on the combustion characteristics and particulate emissions of a diesel engine fueled with DBE (diesel-biodiesel-ethanol) blended fuels. The effects on in-cylinder pressure, heat release rate, combustion duration, diffusion fuel mass, BSPM (brake specific particulate mass) and BSPN (brake specific number concentrations) when diesel-biodiesel is blended with 0%, 5%, 10% and 20% ethanol were tested in a 4-cylinder naturally-aspirated direct-injection diesel engine at a steady state speed of 1800 rev/min under five engine loads. Overall, compared with ULSD (ultra-low-sulfur diesel), DBE blends can effectively reduce BSPM, BSPN and maintain a good trade-off relationship among PM-PN-NOx. Compared with biodiesel, the blended fuels perform better in suppressing BSPN, leading to a reduction in the number of ultrafine and nano-particles. (C) 2015 Elsevier Ltd. All rights reserved.