Abstract: By cyclic voltammetry, electrochemical properties of the boron-doped diamond thin-film electrode were investigated compared with those of Pt/BDD electrode. It shows that the boron-doped diamond thin-film electrode has wide electrochemical window （approximate 3V）, excellent chemical stability and low background current （near zero ）. At the same time, the result was analyzed with energy level theory. All the works show that the boron-doped diamond thin film is a kind of ideal potential electrode.