Lithium is a light metal with outstanding physical and chemical properties with many applications in the modern world. The concentration of lithium in sea water is on average 0.17 ppm and in the effluent of such a unit, it should be increased to 350 ppm on average. In this study, 1-hexyl-3-methylimidazolium [C6mim+] as cation and bis (trifluoromethylsulfonyl) imide [NTf2-] as anion of ionic liquid (ILS) using the neutral tributyl phosphate (TBP) were developed for efficient extraction of lithium ions (Li+) from Salt Lake Brine. The effective parameters on lithium ions extraction process were studied including solution pH (~ 7), adsorbent dosage (100 & 300 mg) and extraction time (30 & 120 min). The extraction efficiency of lithium ion was 94 % fir ILS under the optimal conditions. The adsorption rate, adsorption capacity and mechanism are examined with applying the kinetic, isotherm and free energy models on experimental data. The Langmuir isotherm proposed adsorption capacity of 62.5 mg/g for ILs , respectively. This indicated multi-layer pattern for ILs. Free energy model is suggested a physical sorption mechanism for lithium ions. The obtained results are preformed the green ILs can be used as alternative extractant for Li+ from salt lake brine. Manuscript profile