<p>Shape-selective <i>x</i>% BaO/MCM-22(PI) catalysts were prepared by a high-efficiency pre-impregnation method and investigated for the selective alkylation of toluene and dimethyl carbonate into p-Xylene. <i>x</i>% BaO/MCM-22(PI) catalysts exhibited high shape-selective catalytic performances for the selective synthesis of p-Xylene. Characterization results indicated that the microstructure of MCM-22 was well preserved during the process of pre-impregnation. The external Brønsted acid sites over MCM-22 were efficiently eliminated without influencing the acid sites inside channels. And the pore entrance of MCM-22 was efficiently adjusted by the generated BaO. Catalytic results showed that much higher toluene conversion along with comparative PX selectivity were achieved over <i>x</i>% BaO/MCM-22(PI) compared to that over <i>x</i>% MgO/MCM-22(PI) with the same loading amount&#xa0;of metal oxide. <i>x</i>% BaO/MCM-22(PI) also exhibited much better stability in catalytic activity within 48&#xa0;h on stream. The conversion of toluene as 33.5% and selectivity of PX as 57.9% were attained over the 10% BaO/MCM-22(PI) under the optimal conditions, leading to the highest PX yield of 13.4%. Relatively good modification effects were also received over MCM-22 modified with some other metallic oxides such as La₂O₃ and CeO₂, indicating the universality of the pre-impregnation method.</p>