Two series of gold catalysts supported on TiO2, SiO2, and CeO2 have been prepared by colloidal gold deposition with 2 wt% of nominal gold loading. The diameter of gold particle stabilized by polyvinylalcohol (PVA) or by tannic acid-citrate was 2-3 nm and 6-7 nm, which increased to 5-7 nm and 7-13 urn, respectively. after calcination in air. Catalytic activities were investigated and compared in CO oxidation and glucose oxidation reactions. Inverse correlation was found between the activities in glucose oxidation and CO oxidation suggesting that the mechanisms are different. Besides the high dispersion the nature of the support seems to play a significant role in the liquid phase reaction. (C) 2010 Elsevier B.V. All rights reserved.