An organic-salt of H4SiW12O40, (C10H7NO2)(4)H4SiW12O40, was prepared through the combination of H4SiW12O40 and quinaldic acid. The organic-salt was characterized by element analysis, FT-IR, UV-vis, XRD, SEM, TG, potentiometric titration and NH3-TPD. And its catalytic activity was tested in the synthesis of levulinate esters as a solid acid catalyst. The influences of various reaction conditions such as reaction time, catalyst amount and molar ration of ethanol to levulinic acid on the conversion of levulinic acid were investigated. The organic-salt still maintained the Keggin structure of pure H4SiW12O40 and has strong acidity. It exhibited excellent catalytic performances, including high yield of esters and good reusability. The conversion of levulinic acid could reach 98.6% in the esterification of levulinic acid and ethanol under the optimized reaction conditions. The results showed that the acid strength of catalyst played a very important role in the esterification. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.