In this article, zirconia sulfuric acid (ZrSA) has been synthesized from the reaction of ZrO2 with chlorosulfonic acid. It was characterized by (FT-IR, XRD, TGA, SEM, EDS, BET, BJH, ICP and pH analysis). This catalyst was employed for the synthesis of 3,4-dihydropyrimidinones via cyclocondensation of beta-ketoester, aromatic aldehydes and urea/thiourea under solvent-free conditions. Main advantages of the catalyst were non toxic nature, high stability and reusability. .