TiO2 adsorbents were prepared by hydrolysis of Ti(OC3H7)(4) followed by heat treatment of their hydroxides. Their structures were studied by X-ray diffractometry and Fourier transform infrared spectrometer as a function of preparation pH. The Co2+ adsorption characteristics of the adsorbent in high temperature water were investigated in a stirred autoclave. Co2+ adsorption capacity of the TiO2 adsorbent was determined to be 0.09 mEq/g adsorbent in 280 degrees C of high temperature water. The enthalpy change (Delta H degrees) of about 34 kJ/mol caused by the adsorption of Co2+ on the TiO2 indicates that the adsorption is endothermic in the experimental temperature range (150-280 degrees C). It was shown that specific surface area and surface OH groups of these adsorbents are not dominant factors for Co2+ adsorption on oxides at high temperature.