The synthesis and characterization of sulfated ZrO2 with ordered pores as a solid acid catalyst were investigated. Ordered porous ZrO2 containing sulfate ions was synthesized by hydrolysis of zirconium n-propoxide in the presence of HCl, surfactant and (NH4)(2)SO4 dissolved in distilled water, when the SO4/Zr molar ratio was changed in the range of 0.8-1.4. BET surface area of sulfated ZrO2 thus synthesized was found to be 150-160 m(2) g(-1). The presence of sulfate ions in ZrO2 was confirmed by an appearance of IR band at ca. 1398 cm(-1) in the IR spectra of sulfated ZrO2. Since two IR bands due to surface hydroxyl groups were still observed for sulfated ZrO2, the possibility that sulfate ions are highly dispersed on the surface of ordered porous ZrO2 was suggested. From the evaluation of surface acidity by NH3-TPD measurements, not only the amount of NH3 desorption but also the strength of acid sites related to NH3 desorption temperature were found to be increased with increasing the SO4/Zr ratio up to 1.2. On the other hand, FTIR spectroscopy following pyridine adsorption revealed that the maximum surface density of Bronsted acid sites was attained for sulfated ZrO2 with SO4/Zr ratio of 1.0. Sulfate species interacting strongly with nano-sized tetragonal ZrO2 was considered to be responsible for the creation of Bronsted acid sites. In accordance with the surface density of Bronsted acid sites, sulfated ZrO2 with SO4/Zr ratio of 1.0 showed the highest activity for the skeletal isomerization of 3,3-dimethylbut-1-ene, which predominantly occurs on Bronsted acid sites.