Abstract: Mesoporous aluminosilicates MSU-S_MFI with well-ordered hexa nal symmetry were assembled from MFI zeolitic precursors containing abundant protozeolitic nanoclusters. Normal MCM-41 was synthesized by using tetraethyl orthosilicate (TEOS) and sodium aluminate as silica source and aluminum source,respectively. The pore diameter of MSU-S_MFI sample and normal MCM-41 both are 2.70 nm, and their BET specific surface areas and pore volumes are comparable as seen from XRD and N₂ sorption results. Although both MSU-S_MFI and MCM-41 possess weak acidic sites and medium strong acidic sites in NH₃-TPD profiles, the density of weak acidic sites and medium strong acidic sites in MSU-S_MFI are much higher than that of MCM-41.The catalytic cracking conversion of cumene on MSU-S_MFI is 31％ higher than that on MCM-41 with the same Si/Al ratio, and the butylation conversion of naphthalene over MSU-S_MFI is 15％ higher than that on the MCM-41 sample. Incorporation of MFI zeolitic nanoclusters into the mesostructured framework of MSU-S_MFI led to enhanced acidity.