It is reported for the first time that Pt-Ru/C catalysts were prepared in the ionic liquids. This novel preparation method has some advantages, such as the high electrocatalytic activity of the catalysts for the methanol oxidation, simple preparation procedure, recycle of the ionic liquids, etc. In the best preparation conditions, the electrocatalytic activity of the Pt-Ru/C catalyst prepared in the ionic liquid for methanol oxidation is higher than that of the commercial E-Tek Pt-Ru/C catalyst. It is mainly due to the low crystallinity of the Pt-Ru particles and the abundant Ru oxides on the surface of the Pt-Ru/C catalysts. Therefore, this kind of preparation method of the catalysts has potential applications for the direct methanol fuel cell (DMFC). © 2005 Elsevier Ltd. All rights reserved.