The surface properties of a series of 1-alkyl-3-methylimidazolium (AMIM)-based ionic liquids (ILs) were characterized using an inverse gas chromatography technique at temperatures from 343.15 to 373.15 K. Nine polar and nonpolar probe solvents were used to investigate the surface properties, which included the Lewis acid-base constants, adsorption free energy, enthalpy adsorption, and dispersive component of the surface free energy (4). Furthermore, the effects of the alkyl chain length of the cation and the different anions on the surface properties were also studied. The results indicated that all of the investigated ILs were Lewis amphoteric material with low r(s)(d) values. When the anion was kept as [PF6](-), r(s)(d) of the series of AMIM-based ILs linearly decreased as the alkyl chain length was increased in the imidazolium cation, and the basicity also decreased as the alkyl chain length was increased.