Boundary migration under an electric field was investigated for pure, TiO2-doped, and Li2O-doped Al2O3 specimens. Boundary migration rates in TiO2-doped and Li2O-doped Al2O3 specimens were much faster compared with that of pure Al2O3. In all specimens, the migration rate was observed to depend on the applied bias direction. Compared with pure Al2O3, the dependence of boundary migration on bias direction became more pronounced in TiO2-doped Al2O3 but less pronounced in Li2O-doped Al2O3. The results were explained in terms of the variation of grain sizes, mobility, and electrostatic potential of boundaries because of doping.