The phosphors of (La,Ce,Tb)BO3 were synthesized by high temperature solid state reaction. X-ray diffractometry (XRD) patterns indicate that the crystal structures of (La,Ce,Tb)BO3 and LaBO3 are the same. The crystal structure has not been changed by Ce3+ and Tb3+ doping. Emission scanning electron microscopy (SEM) images show that the particle sizes of phosphors are more uniform, the morphology is more regular, and the granularity is about 5 μm. The content of TbBO3 phase in (La,Ce,Tb)BO3 increases with increasing of Tb content in (La,Ce,Tb)BO3. When Tb concentration reaches 15% and above, the content of TbBO3 phase in (La,Ce,Tb)BO3 increases more rapidly. The luminescence properties of (La,Ce,Tb)BO3 and the sensitization of Ce3+ to Tb3+ were studied. In the excitation spectrum of Ce3+ there are three peaks at 244, 268 and 330 nm, respectively. And in the emission spectrum of Ce3+, there are two peaks at 365 and 380 nm, respectively. All of them have the large overlap. The Maximum emission wavelength of Tb3+ is 541 nm, and its excitation peaks is 230 nm. Both the Tb3+ characteristic emission and excitation peaks and the Ce3+ characteristic emission and excitation peaks were observed in the emission and excitation spectrum of (La,Ce,Tb)BO3. Comparing the excitation spectrum of (La,Ce)BO3 with the emission spectrum of (La,Tb)BO3, it is found that they have the large overlap. It is indicated that there is a remarkable energy transfer from Ce3+ to Tb3+ in (La,Ce,Tb)BO3. When the concentration of Ce or Tb in (La,Ce,Tb)BO3 is fixed, because of concentration self-quenching effect, the relative intensity of main emission peak (at 541 nm)increases firstly and then decreases with increasing of the concentration of Tb or Ce. At fixed ratio of Ce concentration to Tb concentration, the relative intensity of the main emission peak of (La,Ce,Tb)BO3 is the highest when La concentration in (La,Ce,Tb)BO3 reaches 70 mol%. The sample with better luminescence properties will be obtained in the wide range of the concentration ratio of Ce to Tb at fixed La concentration of 80 mol%. When La concentration is 80 mol% and above, the relative intensity of the main emission peak of (La,Ce,Tb)BO3 will be the highest at 3/1 concentration ratio of Ce to Tb