The alkylation of p-cresol with tert-butanol (TBA) to 2-tert-butyl-p-cresol (TBC) catalyzed by a novel multiple-SO3H functioned ionic liquid (IL1) was investigated. Meanwhile, the catalytic activity of this novel ionic liquid was compared with other four traditional ionic liquids. The results showed that IL1 has superior catalytic activity to other four traditional ionic liquids with the conversion of 85.3% and selectivity of 95.2%. Also, the reaction conditions were investigated to obtain the optimum conditions. Operational simplicity, small amount of usage, high activity, reusability and selectivity are the key features of this methodology.