The surface-phase oxides of niobia on silica substrate ((Nb2O5/SiO2), NS(x)) were prepared and characterized. Such oxides were used as supports for palladium catalysts. The one-step synthesis of methyl isobutyl ketone (MIBK) from acetone and hydrogen in liquid phase was also investigated over Pd/NS(x) catalysts, Experimental results indicate that these catalysts were effective for the formation of MIBK; since little of the parallel by-product of isopropanol (IPA) was formed, these catalysts reached selectivities of 88-92% MIBK and 2-3% IPA at 30-35% conversion. The reactivity of Pd/NS(x) declined obviously with an increase of water content that accumulated in a semi-batch reaction system. The water could be partially expelled and the deactivation of catalysts could be improved by using a fixed bed continuous Row reaction system.