The lnfluence of ultrasonic treatment on the coking amount of a nickel-based catalyst(Ni/l2O3)for the reaction of reforming with carbon dioxide of Benzeno was investigated.The results show that ultrasonic treatment modify the pore size distribution of the catalysts significantly and also reduce the amount of coke formed on the catalyst.The reduction in the coking amount is not sensitive to the power output of the ultrasonic treatment device in the power range tested(120 W and 500 W).