The new type of solid superacid S2O82-/SnO2-SiO2 was prepared by precipitation and hydrothermal aging method with ammonium persufate as soaker instead of sulphuric acid. The samples with different tin oxide content were characterized by FT-IR, XRD, BET, TG/DTA and Hammett indicators techniques. Catalytic activities for esterification of butanol and acetic acid were also investigated. As a result, most sulfate-ion in surface of S2O82-/SnO2-SiO2 coordinate with Sn bidentatly, and the acidic strength of S2O82-/SnO2-SiO2 is related to the content of tin oxide. Besides, introducing appropriate Si can improve the combination of the tin with SO42- thus increases the amount of acid. Catalyst S2O82-/SnO2-SiO2 reveals high catalytic activity and stability in the esterification at very large range of composition.