Recently, there has been an increasing interest in ionic liquids (ILs) because they play a considerable role in colloid and interface phenomena as green surfactants [1]. The aim of the present study is to investigate adsorption of 1-heptyl-3-methylimidazolium chloride, briefly [C7mim][Cl] in the presence of sodium and potassium chloride electrolytes at toluene-water interface. To acquire interfacial activity parameters, the experimental data are well fitted by Frumkin adsorption isotherm for concentrations less than critical micelle concentration (CMC).