In　this　paper,　water-miscible　ionic　liquid　(IL)　such　as　1-butyl-3-methylimidazolium　chloride　([BMIM]Cl)　is　introduced　for　the　first　time　as　a　novel　multifunctional　acceptor　phase　additive　in　hollow-fiber　protected　liquid　phase　microextraction　(HF-LPME).　For　investigating　the　performances　of　[BMIM]Cl,　it　was　respectively　mixed　with　NaOH,　HCl　and　deionized　water.　And　their　extraction　performance　was　preliminary　evaluated　with　alkaline　compounds　(clenbuterol,　metoprolol,　carteolol　and　propranolol),　acidic　compounds　(diethylstilbestrol,　hexestrol,　phenol　and　bisphenol　A)　and　neutral　compounds　(acenaphthylene,　fluorene　and　fluoranthene).　Furthermore,　a　complete　extraction　and　determination　method　using　IL-three　phase　HF-LPME　and　liquid　chromatography　was　established　for　polycyclic　aromatic　hydrocarbons　(PAHs)　in　river　water.　The　extraction　conditions,　such　as　concentration　of　IL,　extraction　temperature,　extraction　time,　stirring　speed,　ionic　strength　and　the　addition　of　methanol　were　studied　in　detail.　Under　the　optimum　conditions,　the　linear　ranges　of　acenaphthylene,　fluorene　and　fluoranthene　were　1-100,　1-200　and　1-200　ng　mL(-1),　respectively.　Limit　of　detections　(LODs)　were　lower　than　0.25　ng　mL(-1).　The　recoveries　of　PAHs　in　three　kinds　of　spiked　real　water　are　between　90.97　and　109.7%　and　the　precisions　are　in　the　range　of　2.53-7.01%.　Since　water-miscible　ionic　liquids　had　various　forms,　similar　extraction　capabilities　to　organic　solvents　and　could　be　conveniently　adjusted　by　acid,　alkaline　and　buffer,　this　proposed　method　should　have　great　potentiality　in　sample　preparation　of　HF-LPME.　(C)　2011　Elsevier　B.V.　All　rights　reserved.