Spherical particles of rare-earth doped LaF 3 are synthesized through refluxing in glycerol/water media. The low-voltage cathodoluminescence of LaF 3 : Eu due to 5 D 0 → 7 F 1 and 5 D 0 → 7 F 2 transitions was found to be sensitive to the site that Eu 3+ ions occupied. The luminous efficiency of LaF 3 :Ce 3+ , Tb 3+ with green emission is improved from 1.53 to 2.02 lm/W compared with LaF 3 :Tb 3+ , due to the energy transfer processes from Ce 3+ to Tb 3+ ions. Our results suggest that the obtained spherical particles of rare-earth doped LaF 3 are promising as highly efficient low-voltage cathodoluminescent phosphors, which have received considerably less attention.