The transfer of copper ions into the Sulfonated Polysulfone (SPSF) cation-exchanger membrane coated on rotating disk electrodes in 0.007 M CUSO₄ - 5H₂O - 0.5 M H₂SO₄ solution was investigated with using cyclic voltammetry (CV) and electrochemical impedance spectroscopy. Impedance value obtained from AC impedance method could be adapted to the proposed equivalent circuit model and was consistent with calculated values obtained by non-linear least square fitting method. Both transport (diffusion coefficient) and interfacial parameters (charge transfer resistance and double layer capacitance) were investigated with the reduction potential and rotation rate of electrode. The diffusion coefficient obtained by curve-fitting to experimental result is D = 6.498 ×10^(-11) ㎠^s^(-1) at open circuit voltage. The charge transfer resistance, double layer capacitance, and bulk membrane resistance showed dependence on reduction potential, but no dependence on rotation rate of electrodes.