Our group has reported the synthesis of hydrothermally stable mesoporous aluminosilicates (MAs) by self-assembly of triblock copolymers and zeolite Y precursors. However, degradation of zeolite Y precursors in the acidic synthesis system will inevitably lead to low microporosity fraction of final products. Development of a facile route to obtain MAs simultaneously with high hydrothermal stability and microporosity fraction is still a great challenge. Herein, we employ zeolite Beta precursors as building units to solve this problem. In this strategy, zeolite Beta precursors were more stable than zeolite Y precursors in the acidic synthesis system due to the presence of organic directing agent TEAOH, which would result in more microporosity implanted into the framework of MAs. By fine-tuning the assembly time, the microporosity fraction could be adjusted in a range of 38.7%-52.9%. In addition, the synthesized MAs maintain well-resolved crystal patterns, high surface area, and pore volume even after a severe hydrothermal treatment.