Ozone induced chemiluminescence (CL) of acridone in acetic acid is investigated. From preliminary spectral observations the CL emission is determined to be due to energy transfer from an excited species to acridone which emits at its fluorescence wavelength. UV-vis. spectra of the excited species as well as some of the products are obtained. From kinetic observations of the system, a reaction sequence according to which CL is produced upon reaction of an intermediary with ozone, is proposed. This intermediary is produced upon reaction of an initial oxidation product of acridone with another acridone unit and it is thought to be 10,10'biacridonyl. The rate constant of the first reaction step is determined to be ≃ 30 M^-1 · sec^-1.