Liquid-phase alkylation of benzene with cyclohexene to cyclohexylbenzene was investigated using SiO2-grafted AlCl3 catalysts prepared by the chemical vapor deposition method. The SiO2-grafted AlCl3 catalysts were active at a temperature as low as 0 degrees C and were tractable in handling when they were repeatedly used for the catalytic reaction. Although their catalytic activities were gradually lowered by repetition of the catalytic runs, the catalysts were able to repeatedly apply to the catalytic reaction until the turnover number exceeded 110. The liquid-solid heterogeneous reaction was probably limited by diffusion steps of reactants and/or product in porous catalysts. An ultrasonic vibration during the course of catalytic reaction gave an accelerating effect in such a way that the reaction rates were increased up to about one order of magnitude, compared to those in cases without ultrasonic vibration. The cause of the accelerating effect was discussed from the results which were obtained in the experiments by using several catalysts with different sizes in the particle diameter and in the pore diameter.