The excited states of benzophenone adsorbed on well-characterized Ti−Al binary oxides were investigatedby means of conventional molecular spectroscopic techniques such as UV and IR absorption as well asphotoluminescence spectra measurements. It was found that the photochemical and photophysical propertiesof benzophenone adsorbed on the oxide surfaces strongly depend on their surface properties, which aresystematically changed by changing the composition of the oxides. Specifically, the phosphorescence spectraof benzophenone adsorbed on the oxides have been found to be composed of the hydrogen-bondedbenzophenone species and the protonated benzophenone species.