In order to obtain a useful expression for the kinetics of the photocatalyzed total oxidation reaction of olefines with TiO2 as the catalyst, the dependence of reaction rate on the concentration of the educt species, the absorbed irradiation intensity, the wavelength of the light and the temperature was investigated. The experiments were performed in a CSTR system. The results obtained for steady-state conditions showed that besides the photocatalytic activity, the TiO2 powder fixed on one wall of the reactor has, in addition, a thermal activity for higher temperature. Although the reaction behavior of the system is relatively complex, it can be modeled straightforward by a concept proposing a cooperative coadsorption of oxygen and the olefine species mediated by the electron/hole pairs generated by the absorbed light on the semiconductor's surface.