Heterogeneous catalysts have attracted considerable interest from both environmental and economical points. The solid acids have high turnover numbers (TON) and easily separated from reaction mixtures.1-2 Design, synthesis and applications of catalytic systems have more demand, because catalysis has played a major role in the preventing of pollution in our environment. Therefore , we wish to report synthesis of a novel nano-sized solid acid namely nono meta silica sulfuric acid (NMSSA) as a heterogeneous catalyst for the multicomponent synthesis such as 3,4-dihydropyrimidin-2(1H)-ones in excellent yields and short reaction time.3 NMSSA was synthesized from silicate anion and chlorosulfonic acid (Scheme 1). The described solid acid was characterized by XRD, FT-IR, TEM and SEM. We thought that the abovementioned nano solid acid is an alternative for heteropoly acids and have potential for industrial production.