According to a space-charge theory analysis, the space-charge potential of YSZ is negative, which corresponds to an Y-Zr’ segregation and an V-O(..) depletion in the space-charge layers. Owing to the highly disordered structure of the grain-boundary interfaces, the resistance of the interfaces is considered to be negligible with respect to that of the space-charge layers, the intrinsic grain-boundary resistivity in stabilized-ZrO2 was thus considered to originate from the V-O(..) depletion in the space-charge layers, and an intrinsic grain-boundary resistivity model was developed. With this model, all the grain-boundary resistivity behaviors in stabilized-ZrO2 with high-purity described in the published litteratures were satisfactorily explained.