(Y,Gd)BO 3 :Eu powders were prepared by conventional solid-reaction method. Surface-modified (Y,Gd)BO 3 :Eu powders with MgF 2 were prepared by the emulsion method. The best preparing way is that MgCl 2 was dropped to the mixture of NH 4 F and (Y,Gd)BO 3 :Eu powders to prepare surface-modified (Y,Gd)BO 3 :Eu powders. The interaction between F − ions and the phosphor particles was discussed. It is shown that the structures of surface-modified (Y,Gd)BO 3 :Eu powders were measured by XRD. The luminescent properties of (Y,Gd)BO 3 :Eu powders with MgF 2 are researched.