Abstract: Mesoporous molecular sieves MCM-41 was facilely synthesized at room temperature under normal pressure. Then,it was used to hydrothermally prepare a series of sulfonated MCM-41 mesoporous solid acids with sulfuric acid as sulfonating agent.The samples were characterized by TG,XRD,FT-IR,and TEM-EDX. The acid density was measured by base titration. Furthermore,their catalytic properties were evaluated with the synthesis of ethyl levulinate as a probe reaction. The results showed that the resulting MCM-41-SO₃H catalysts maintained the mesoporous structure of MCM-41,although the hydrothermal process reduced the mesoporous regularity to a certain extent. Meanwhile,the hydrothermal time and temperature affected their acid density,which in turn affected the catalytic activity. The catalyst hydrothermally prepared at 180℃ for 21 h exhibited the highest catalytic activity,and the corresponding conversion of levulinic acid as high as 74.4%. In addition,the resulting mesoporous solid acid also displayed satisfactory cyclic stability.