Two different means were employed to prepare nanoparticle TiO2-pillared montmorillonite. One was the conventional ion exchange method and the other was post hydrothermal treatment after ion-exchange. The calcined clay was characterized by different physicochemical techniques such as XRD, DSC-TG and nitrogen adsorption-desorption. The results demonstrate that the conventional ion-exchange method causes the titania pillared montmorillonite clay to have relatively large surface area and pore volume. The post hydrothermal treatment method gives rise to better crystallographic form, bigger crystallite and more stable pillared montmorillonite clay. Higher temperature results in shorter reaction time and better crystallographic form of anatase.