Gold deposited on various oxides with high dispersion was found to be active for the hydrogenation of CO2 at temperatures between 150 and 400 degrees C. Product selectivities greatly depended on the nature of support oxide. Acidic oxides like TiO2 gave higher CO2 conversions but low methanol yields. Zinc oxide component was indispensable for selective methanol synthesis. Significantly, large particle size effect of gold was observed and smaller gold particles gave higher methanol productivity per exposed surface area of gold. This can be explained by an increase in the perimeter area of gold particles with a decrease in particle size. Methanol yield was greatly enhanced in a Au/ZnO-TiO2 catalyst probably due to an increase in gold-zinc oxide interface.