The prepared catalysts consisted of REY zeolite (15 wt.-%) and kaolin clay. The preparation was performed by hydrothermal hot pressing (HHP) at different temperatures, and the catalytic cracking and physicochemical properties of these samples have been investigated intensively. The catalytic conversion and selectivity for gasoline in the pentadecane and heavy oil cracking on these samples treated by HHP at different temperatures (25-220 degrees C) varied significantly, in contrast to those on the sample without HHP treatment. In particular, the catalyst treated at 170 degrees C exhibited high catalytic activity and selectivity for gasoline, low coke formation, and high compressive strength. These results suggest that HHP may be important for preparing cracking catalysts with high catalytic conversion and low price as a new route. X-ray diffraction (XRD) studies showed that the REY zeolite in the catalysts was stable during the HHP at temperature from 25 to 170 degrees C, and increasing the temperature to 220 degrees C resulted in partial destruction of REY zeolite crystalline. Characterization of physicochemical properties showed that the density, compressive strength, and the most probable pore diameter of the various samples increased with the HHP temperature. The surface area of various samples basically remained the same at the HHP temperature of 25-170 degrees C, and the surface area decreased remarkably by increasing the HHP temperature to 220 degrees C. IR spectra of pyridine adsorbed on these showed that there were both Bronsted and Lewis acid sites, and the TPD-NH, studies indicated that the acid strength increased. The relative difference in the catalytic performance for cracking reactions is discussed, and is assigned to the following possible factors : (A) the variation in the acid types such as Bronsted and Lewis sites, acid concentration, and acid strength; (B) the destruction of REY zeolite crystallites; (C) the change in some physicochemical properties.