Silica gel as an accessible substrate with high surface area can be modified by propyl sulfonic acid. Silica-functionalized sulfonic acid (SiO2-Pr-SO3H) as a highly efficient heterogeneous solid acid catalyst catalyzes various organic reactions and can be removed easily, recovered and reused without significant loss of activity. In this review, preparation and application of SiO2-Pr-SO3H in organic synthesis is investigated. (C) 2014 Elsevier B.V. All rights reserved.