Five　acidic　Imidazolium　ionic　liquids　(ILs)　were　synthesized　and　the　catalytic　activity　for　the　preparation　of　sec-butanol　via　the　transesterification　of　sec-butyl　acetate　(SBAC)　with　methanol　were　investigated.　Among　them,　1-(3-sulfopropyl)-3-methylimidazolium　hydrogen　sulfate　([HSO3-PMIM]HSO4)　performed　best.　In　the　batch　reactor,　the　influences　of　various　reaction　conditions　on　the　transesterification　were　investigated　using　[HSO3-PMIM]HSO4　as　catalyst.　Under　the　optimal　reaction　conditions,　the　conversion　of　SBAC　was　89.30%.　In　addition,　in　order　to　enhance　the　conversion　of　SBAC,　reactive　distillation　was　carried　out　in　the　presence　of　[HSO3-PMIM]HSO4　as　catalyst.　A　high　conversion　of　the　SBAC　of　97.72%　was　obtained　under　the　optimal　reaction　conditions.　In　order　to　evaluate　the　catalyst　stability,　the　ILs　was　repeatedly　used　for　5　times　without　obvious　loss　of　activity　after　simple　separation　from　the　mixture.　The　results　indicated　that　[HSO3-PMIM]HSO4　showed　better　catalytic　activity　and　reuse　performance.　Therefore,　an　environmental　friendly　technology　for　the　preparation　of　sec-butanol　catalyzed　by　ILs　is　provided.　(c)　2014　Elsevier　B.V.　All　rights　reserved.