SO 24? /TiO2-La2O3, a novel solid superacid, was prepared and its catalytic activities at different synthetic conditions are discussed with esterification of n-butanoic acid and n-butyl alcohol as probing reaction. The optimum conditions have also been found, mole ratio of n(La3+):n(Ti4+) is 1:34, the soaked consistency of H2SO4 is 0.8 mol/L, the soaked time of H2SO4 is 24 h, the calcining temperature is 480 °C, the calcining time is 3 h. Then it was applied in the catalytic synthesis of ten important ketals and acetals as catalyst and revealed high catalytic activity. Under these conditions on which the molar ratio of aldehyde/ketone to glycol is 1:1.5, the mass ratio of the catalyst used in the reactants is 0.5%, and the reaction time is 1.0 h, the yields of ketals and acetals can reach 41.4%～95.8%. SO24? / TiO2-La2O3, a novel solid superacid, was prepared and its catalytic activities at different synthetic conditions are discussed with esterification of n-butanoic acid and n-butyl alcohol as probing reaction. The optimum conditions have also been found, mole the ratio of n (La3 +): n (Ti4 +) is 1:34, the soaked consistency of H2SO4 is 0.8 mol / L, the soaked time of H2SO4 is 24 h, the calcining temperature is 480 ° C, the calcining time is 3 h . Then it was applied in the catalytic synthesis of ten important ketals and acetals as catalyst and revealed high catalytic activity. Under these conditions on which the molar ratio of aldehyde / ketone to glycol is 1: 1.5, the mass ratio of the catalyst used in the reactants is 0.5%, and the reaction time is 1.0 h, the yield of ketals and acetals can reach 41.4% ~ 95.8%.