Nanosized hierarchical micro/mesoporous composites were successfully fabricated using non-ionic block copolymer Pluronic P123 and protic ionic liquid (butylamine acetate) as the co-templates. The obtained samples were characterized by several techniques, including small angle X-ray scattering, N2 gas sorption, scanning electron microscope and transmission electron microscopy. The result established that the final silica materials possessed a disordered population of micropores coexisting with two different mesoporous channels of 4.0 and 7.3 nm. The formation mechanism of the micro/mesoporous silica which is based on the interaction between PIL and P123 is tentatively elucidated. 12-Tungstophosphoric acid catalysts incorporated into these micro/mesoporous materials were prepared by impregnation, and their catalytic performances were investigated in the alkylation of o-xylene with styrene. Alkylation results exhibited that all the catalysts showed the high catalytic performance in terms of propane conversion and selectivity to propene.