Abstract: Based on transfer matrix method, the effects of doping on one-dimensional photonic crystal are researched numerically. It is shown that in doped photonic crystal, there is a conduction band in the center of band gap, and the depth of conduction band varies gradually with the doping position and refractive index. When the crystal structure is given, there is always a doping position which makes the conduction band depth maximal in the center of band gap. When the doping position is given, there is always a specific value of impurity refractive index which makes the conduction band depth maximal in the center of band gap. These characteristics of one-dimensional photonic crystals are applied for the design of filters and optical resonators.