Aqueous biphasic systems containing ionic liquids (ILs) attract rather high attention; in particular their application in liquid-liquid extraction is very attractive due to the specificity of the systems and great possibilities in the modification of IL chemical structures. In the present work, a series of amino acid ionic liquids (AAILs) based on the 1-alkyl-3-methylimidazolium cation and L-glutamic acid anion [C(n)mim][Glu] (n = 4, 6, 8) were synthesized. Densities, refractive indices, and specific electrical conductivities of aqueous solutions of these AAILs in the concentration range 0-70 wt % (for [C(4)mim] [Glu] solutions up to 87 wt %) were measured at temperature 298.15 K and ambient pressure 0.1 MPa. The liquid-liquid equilibria for ternary solutions [C(n)mim][Glu] + salt (K2CO3) + water at 298.15 K were under study. In aqueous solutions of [C(8)mim] [Glu] micellization is observed, whereas [C(4)mim] [Glu] and [C(6)mim] [Glu] in aqueous solutions form small ordinary aggregates. The critical micellar concentration for [C(8)mim][Glu] aqueous solutions at 298.15 K was estimated from the experimental data on the concentration dependence of the specific electrical conductivities of the solutions.