Several amine-functionalized cation ILs were successfully synthesized, characterized and tested for CO₂ absorption studies. Non-functionalized ILs were studied for comparison purpose. The primary amine-ILs have shown higher CO₂ solubilities both on molar basis (mol of CO₂/mol of IL) and on volume basis (g of CO₂/L of IL), compared to non-functionalized and tertiary-amine ILs. Besides amine-functionalization of the cation, anion of the IL has strong influence on CO₂ solubility due to its contribution by physical absorption. As a result, the [TF₂N]-anion amine-ILs have higher CO₂ solubility than [BF₄]-anion amine-ILs. Among non-amine functionalized ILs, [P_(14)666][TF₂N] has the highest CO₂ solubility.