Extractive　denitrification　(EDN)　of　shale　oil　using　ionic　liquids　(ILs)　as　the　extracting　agent　has　good　industrial　prospects.　In　such　processes,　ILs　with　higher　selectivity　to　N-compounds　and　lower　solubility　in　shale　oil　are　desired　to　improve　the　EDN　efficiency,　and　reduce　the　loss　of　ILs　and　the　contamination　of　shale　oil.　In　the　present　study,　we　employed　COSMO-RS　to　calculate　the　selectivity　of　70　ILs　to　the　typical　N-compounds　(pyridine,　quinoline　and　indole).　The　influence　of　the　IL　structural　characteristics,　composition　of　shale　oil　and　properties　of　N-compounds　are　investigated　from　a　micro-level　view　with　the　sigma-surface　and　sigma-profile.　The　selectivity　strongly　depends　on　anionic　species　and　it　is　greatly　influenced　by　hydrogen　bonding　(HB)　and　pi-pi　interaction　between　N-compounds　and　ILs.　ILs　composed　of　[H2PO4](-)　and　[MeSO3](-)　with　larger　HB　donor　energy　show　higher　selectivity　to　the　basic　N-compounds,　while　ILs　composed　of　[Ac](-)　with　larger　pi-electron　cloud　density　show　higher　selectivity　to　the　non-basic　N-compounds.　Anions　with　stronger　polarity　have　lower　solubility　in　shale　oil.　Moreover,　experimental　determinations　of　EDN　indicated　that　[C(4)py][H2PO4]/[C(4)mim][H2PO4]　and　[C(2)mim][Ac]/[C(2)py][Ac]　have　good　EDN　performance　for　quinoline/pyridine　with　efficiency　of　100%　and　for　indole　with　efficiency　of　91%,　respectively.　This　work　presents　a　theoretical　basis　to　design　and　select　ILs　having　higher　selectivity　for　N-compounds　and　lower　solubility　in　shale　oil　for　use　in　denitrification.