The anodic behavior of neodymium in acidic Al Cl3-1-ethyl-3-methyl-imidazolium chloride(Al Cl3-EMIC) ionic liquid was investigated by conducting linear sweep voltammeter and chonopotentiometry. The viscosity of Nd dissolved ionic liquid and the surface morphologies of Nd were characterized using an Ostwald viscometer and a scanning electron microscope, respectively. The chemical composition of Nd surface was indentified by Raman spectra. The results showed that dissolution of Nd under anodic polarization occurred after the breakdown of oxide films. A viscous layer formed at the interface of Nd/ionic liquid during the galvanostatic process of 5 and 20 m A/cm2. The formation of viscous layer was attributed to the accumulation of Nd dissolved Al Cl3-EMIC ionic liquid, which had high viscosity. The oxide films could be removed thoroughly and the surface of Nd was homogeneous without etching pits, when viscous layer formed in the anodic process. Otherwise, the surface showed a pitting morphology. The anodic behavior of neodymium in acidic Al Cl3-1-ethyl-3-methyl-imidazolium chloride (Al Cl3-EMIC) ionic liquid was investigated by conducting linear sweep voltammeter and chonopotentiometry. The viscosity of Nd dissolved ionic liquid and the surface morphologies of Nd were characterized using an Ostwald viscometer and a scanning electron microscope, respectively. The chemical composition of Nd surface was indentified by Raman spectra. The results showed that dissolution of Nd under anodic polarization occurred after the breakdown of oxide films. A viscous layer formed at the interface of Nd / ionic liquid during the galvanostatic process of 5 and 20 m A / cm2. The formation of viscous layer was attributed to the accumulation of Nd dissolved Al Cl3-EMIC ionic liquid, which had high viscosity. The oxide films could be removed thoroughly and the surface of Nd was homogeneous without etching pits, when viscous layer formed in the anodic process. Otherwise, the surface showed a pitting morph ology.