Natural mordenite, replacing the synthetic zeolites, has been employed as the support of TiO2, and its photocatalytic activity has been examined in methyl orange (MO) aqueous under UV light. AFM, TEM, XRD, IFTIR and fluorescence spectra have been used to reveal the loading effects of TiO2 on mordenite. The results show that the photocatalytic degradation (PCD) reaction rates are sharply increased by natural zeolite supports. Since mordenite is photo-inert, the PCD-enhancement is mostly caused by the bonding effects of Ti-O-Si and Ti-O-Al. Moreover, another two distinct natural zeolites have been employed as the supports of TiO2, in order to check the universality of PCD-enhancement effect of natural zeolites on TiO2. And the factors of PCD reaction on TiO2-zeolite, such as pH and catalyst dose, have been investigated. (C) 2007 Elsevier B.V. All rights reserved.