The quantitative analyses for our proposed potential-barrier model are given in this paper. The results quantitatively explain how the semiconductiong BaTiO3 ceramics transforms from PTC effect to GBBL capacitor. The designs of PTC resistors and GBBL capacitors from this model are made, and the design properties are much better than that of present experimental data. The mathods improving the properties of relevant devices are discussed. The model provides a theoretical basis for the design, manufacture and property improvement of semiconducting BaTiO3 ceramic devices.