The influence of treatment with an NaAlO2 aqueous solution of NaAlO2 on the surface acid properties of zeolite was studied as a method to increase the number of both Bronsted and Lewis acid sites. The H samples, prepared by, treating with an aqueous solution of NaAIO(2), were characterized by, XRD, NH3-TPD, pyridine-IR, Si-29 MAS NMR, and Al-27 MAS NMR. The surface properties of the HP zeolite changed after treatment with the aqueous NaAlO2 solution: the number of strong and weak acid sites, the total amount of acid, and the Bronsted and Lewis acid sites increased. The treatment of zeolite with an aqueous solution of NaAlO2 may, realuminate an Si(OAI)(A) site by the isomorphous substitution of Al(OH)(4)(-) anions.