The　selective　removal　of　H2S　from　CO2-contained　gaseous　mixture　is　an　important　and　challenging　task　for　natural　gas　industry.　Herein,　1-ethyl-3-methylimidazolium　chloride　([Emim]Cl)　+　imidazole　DESs　were　examined　as　the　physical　solvents　for　H2S　and　CO2　absorption.　The　solubilities　of　gases　were　determined　systematically,　and　the　Henry＇s　constants　of　gases,　ideal　selectivities　of　gas　pair,　enthalpy　changes　of　gas　absorption　were　calculated.　The　variations　of　H2S　and　CO2　solubilities　with　[Emim]Cl　contents　in　DESs　show　different　trends.　In　addition,　the　H2S　solubilities　in　the　[Emim]Cl　+　imidazole　DESs　are　much　higher　than　those　of　CO2.　The　results　were　compared　with　other　liquid　solvents,　and　[Emim]Cl　+　imidazole　DESs　enable　extremely　high　efficiency　for　H2S　absorption　and　large　selectivity　towards　CO2.　The　molecular　dynamics　(MD)　simulations　and　density　functional　theory　(DFT)　calculations　were　then　systematically　carried　out　to　explain　the　results　obtained.　It　is　demonstrated　that　the　strong　interaction　was　found　between　the　H　of　H2S　and　Cl−　of　[Emim]Cl,　which　contributes　to　the　excellent　performance　of　[Emim]Cl　+　imidazole　DESs　in　separation　of　H2S　from　CO2.　©　2021　Elsevier　B.V.