Luminescent Properties of Calcium Silicate Codoped with Td and Gd Yu Lixin Li Dianchao Cao Lin Lect.,School of Materials Science and Technology,Jilin University,Changchun 130026,China.Polycrystallined powder of CaSiO 3 singly doped with Tb and codoped with Td and Gd was prepared with solid state reaction method at high temperature.Its properties were studied.CaSiO 3∶Tb possesses blue light emission due to 5D 4- 7F 6 transition and green light emission due to 5D 4- 7F 5 transition in visible light regions at excitation of 365 nm.Corresponding to concentration of Tb 3+ increasing, energy level of 5D 3 quenched and 5D 4 enhanced. Luminescence intensity of Tb 3+ greatly enhanced after doping Gd 3+ .Because of energy level matching ,luminescence of Tb 3+ is sensitized by Gd 3+ through resonance energy transfer of nonradiation.CaSiO 3; Tb; Gd; sensitized luminescence