Electrochemical Impedance Spectroscopy (EIS), is a confirmed tool for investigation of electrode/electrolyte interfaces and surface-modified electrodes. In the present work, we apply this approaching way to obtain a deeper insight into the electrochemical oxidation mechanism of the glucose in alkaline media. We studied the EIS response of gold nanoparticles embedded in carbon paste and use it as an electrode for the electro-oxidation of glucose. The results were compared with those of a polycrystalline gold electrode. In order to determine the polarization potentials for EIS tests, cyclic voltammetry is first conducted in 0.3 M KOH with 10 mM glucose, recorded at a scan rate of 1 mVs-1. Three polarization potentials were chosen, corresponding to: the open circuit potential (OCP), glucose oxidation and gold oxide formation respectively.