Abstract: The system of ionic liquid and electrode is simplified by the model of equivalent circuit and threecharacteristic frequencies and physical meanings in electrode polarization effects are analyzed. Based on dielectric spectroscopy data, we obtain the basic equivalent circuit parameters： bulk capacitance, bulk resistance and double layer capacitance, dielectric parameters of ionic liquid and electrical double layer, as well as physical parameters related on ion mobility： diffusion coefficient, mobility, effect number density, which play the important significance in depth understanding charge transport mechanism and electrical double layer property of ionic liquid.

Key words: ionic liquid, equivalent circuit, electrode effect, electrical double layer, dielectric spectroscopy