Densities,　rho　and　viscosities,　eta　of　N,N-dimethyl-N-(3-sulfopropyl)cyclohexylammo-nium　tosylate　([CyN1,PrSO3H][Tos]　with　water　and　methanol　were　measured,　at　temperatures　from　303.15　K　to　328.15　K　with　5　K　interval　and　0.1013　MPa,　as　a　function　of　[CyN1,1PrSO3H][Tos]　molality　(or　mass　fraction).　The　isobaric　thermal　expansion　coefficient,　molecular　volume,　standard　molar　entropy,　and　lattice　energy　of　the　pure　IL　were　obtained　based　on　the　density　data　of　pure　IL.　The　apparent　molar　volume,　V　phi,　infinite　dilution　apparent　molar　expansibility,　E;　and　energy　barrier,　E　were　calculated　from　the　experimental　data.　The　Redlich　-Mayer　equation　was　used　to　evaluate　infinite　dilution　apparent　molar　volume,　V.　In　addition,　viscosities　can　be　described　satisfactorily　by　Vogel-Fulcher-Tammann　(VFT)　equation.　The　V;　values　of　the　IL　in　water　are　higher　than　those　in　methanol,　which　suggests　that　the　ion　-solvent　interactions　for　[CyN1,(1)]PrSO3H][Tos]　+　water　binary　system　are　stronger　than　those　for　[CyN1,1PrSO3H][Tos]　+　methanol.　And　the　energy　barrier　values　decrease　with　the　drop　of　IL　mass　fraction　in　both　systems,　indicating　that　the　viscosity　changes　of　binary　mixtures　are　more　sensitive　to　the　temperature　at　high　composition　of　the　IL　(C)2016　Published　by　Elsevier　B.V.