In this work, two imidazolium based ILs, 1-butyl-3- methylimidazolium hydrogen sulfate bmimHSO 4 and 1-butyl-3- methylimidazolium acetate bmimAc were blended with Chitosan (CS) to synthesize the CS-IL-TPP microparticles. The prepared microparticles were characterized by Zetasizer, FTIR, TGA, SEM and elemental analysis (EDX). The addition of these ILs resulted in controlled sized microparticles which possessed good thermal stability. The elemental analysis indicated that the better crosslinking of tripolyphosphate (TPP) with CS was achieved in the presence of IL, bmim Ac as compared with bmim HSO 4 and CS-TPP formulation alone. The better crosslinking might result in the formation of stable and compact microparticles which could have a better control over the drug release applications. Therefore, this kind of IL might be suitable for improving the characteristics of chitosan as a drug carrier which could ultimately provide controlled release of unstable drugs. © Published under licence by IOP Publishing Ltd.