Terbium doped tantalum oxide (Tb-Ta2O5) particles were synthesized with a low hydrothermal method. The phase structure of Tb-Ta2O5 obtained was performed by X-ray diffraction (XRD). The result revealed that the terbium doped Ta2O5 belongs to orthorhombic crystal. The electrochemical property of methylene blue (MB) at Tb-Ta2O5 film electrode in 0.5 mol dm-3 KCl aqueous solution was investigated with cyclic voltgrammetry (CV). The CV result indicated that the electrochemical kinetics of MB was diffusion controlling at Tb-Ta2O5 film electrode. Tb dopping imporved the electrochemical property of Ta2O5 film electrode. Tb-Ta2O5 is used as a kind of electrode material which has some new potential applications.