Isobaric　vapor-liquid　equilibrium　(VLE)　of　sec-butyl　acetate　+　para-xylene　binary　system　and　methyl　acetate　+　para-xylene　+　sec-butyl　acetate　+　acetic　acid　quaternary　system　were　determined　at　1013　kPa　in　a　modified　Rose　still,　so　as　to　provide　a　basis　for　the　design　and　simulation　of　the　separation　process　of　acetic　acid　dehydration　system.　In　the　present　study,　the　L-W　integral　test　was　used　to　check　the　thermodynamic　consistency　of　binary　VLE　data.　The　results　indicated　that　the　thermodynamic　consistency　of　binary　VLE　data　measured　in　this　paper　was　satisfactory.　Furthermore,　binary　experimental　data　were　correlated　well　by　three　models,　which　are　the　NRTL,　Wilson　and　UNIQUAC　models,　respectively.　Subsequently,　the　corresponding　binary　interaction　parameters　of　each　model　were　obtained.　In　addition,　the　NRTL　activity　coefficient　model　in　combination　with　Marek-Standart　chemical　theory　was　used　to　predict　the　quaternary　system　VLE　data　for　the　association　of　acetic　acid.　(C)　2015　Elsevier　B.V.　All　rights　reserved.