Sulfamic acid stabilized on the surface of silica by the n-propyl organic group linker which is named silica-bonded N-propylsulfamic acid was applied as an efficient heterogeneous catalyst with good recyclability and reusability for direct benzylation of 1,3-dicarbonyl compounds using secondary aromatic alcohols or styrenes as alkylating agents in high yields and short reaction times. All the reactions were carried out in nitromethane as solvent under an air atmosphere. The catalyst showed reusable feature by six times without a significant loss in its activity.