Pseudo-boehmite (r-AlOOH) samples havig various crystal structures, suitable surface areas, and porosities were prepared under various synthetic conditions from an aqueous solution of aluminum chloride and sodium hydroxide. The rellationship between the characteristics of the sample and its synthetic conditions was investigated in this study. Pseudo-boehmite was formed in the pH range from 7.6 to 9.6, while bayerite [Al(OH)3] formed over pH 10.6. The pore size of the pseudo-boehmite increased at higher values of pH of hydrolysis (up to pH 9.6) and higher aging temperatures. As the pore size of pseudo-boehmite increased, its BET surface area and excess water decreased, while its pore volume increased. Poorly crystallized boehmite, called pseudo-boehmite, formed with a small crystal size, broadened X-ray peak widths, and excess water in the interlayer of the boehmite structure [1]. In this study, e prepared various gel precipitates by varying the hydrolysis pH, aging temperature, and the aging time. The forming pH range of psudo-boehmite was confirmed by analyzing the XRD and FT-IR spectra; a decrease in the excess water showed, through FT-IR spectroscopic analysis, with increases of the aging temperature. SEM images showed the morphology changes of pseudo-boehmite according to the hydrolysis pH and aging temperature. The pore size, distribution, and specific surface area were investigated using the BET method.