An active direction for new material chemistry is a low temperature method of synthesizing inorganic glasses by the sol-gel process. Since the process occurs at room temperature, it is possible to encapsulate a wide variety of photofunctional organic and organometallic molecules in the inorganic matrix. Consequently, the process is a potential method for new applications such as solid-state lasers, solar light guide, and photodevices using photochromism or photochemical hole burning which include organic substances. This paper reviews the fluorescence spectra of mixed aromatic molecules during the sol-to-gel-to-xerogel transitions of metal oxides. The characteristic nature observed in their fluorescence spectra arises from the electronic perturbation and steric (or conformational) hindrance effects of the surrounding matrices upon the excited states.