In this study, the adsorption properties of a Pt-decorated -Al2O3 (110) surface (Pt-alumina) were investigated to determine the favorable sublayer for Au adsorption using first principles calculations. After full structural relaxation of various configurations, our calculated results indicated that the lowest binding energy and the distance between the Pt atom and the nearest atoms in the alumina (O atom) were −1.87 eV and 2.36 Å, respectively. Finally, the adsorption energy, geometry, and electronic structure for the adsorption of an Au atom onto pure (Au-alumina) and Pt-decorated alumina (Au/Pt-alumina) were examined. The binding energy for the Au/Pt-alumina system was −3.06 eV, which is more than that for the Au-alumina system (−1.40 eV). Therefore, the results from our first principles calculations predict that the Au atom adsorptive capability on Pt-alumina is better than that of pure alumina.