Acid-base properties of aluminas prepared by thermal treatment of a hydrated CTA-product at 600 degrees C were studied. The CTA-oxides, representing gamma-Al2O3, were shown to contain terminal and bridged OH-groups. The concentration of the terminal OH-groups in the CTA-oxides was found to exceed their concentration in gamma-Al2O3 prepared by dehydration of the "precipitated" pseudoboehmite, whereas the concentration of the bridged OH-groups in the CTA-oxides was lower than that in gamma-Al2O3 prepared from pseudoboehmite. The total concentration of the surface Lewis acid sites in CTA-oxides varies within the limits of 2.80-4.14 mu mol/m(2) and is essentially above that in gamma-Al2O3 (2.25 mu mol/m(2)). The distinctive feature of the CTA-oxides is that their surface contains strong Lewis acid sites with nu(CO) = 2220 and 2238 cm(-1). The total concentration of basic sites in the CTA-oxides is lower than that in gamma-Al2O3, however, in contrast to gamma-Al2O3, they contain strong basic sites with nu(CDCl3) = 2200 cm(-1).