The dielectric properties of barium titanate referred to here refer primarily to the dielectric properties of barium titanate ceramics. The dielectric properties of barium titanate ceramics are basically similar to those of barium titanate single crystals. However, because of the polycrystalline structure of ceramics, there are grains and grain boundaries. The size and disordered orientation of grain, the presence of glass phase and impurity in grain boundary directly affect its dielectric properties, making it different from that of single crystal.