The phosphate glass doped with Gd^3＋, Tb^3＋ and Gd^3＋/Tb^3＋ were prepared by high temperature melting. The photo-luminescence behavior of Gd^3＋ and Tb^3＋ in phosphate glass were investigated by absorption, excitation, and emission spectroscopy. Energy transfer between Gd3＋ and Tb3＋ in phosphate glass was studied, and it was found that there were two energy transfer mechanisms between Gd3＋ and Tb3＋ in phosphate glass： one was from 4f7 level of Gd3＋ to the 4f8 level of Tb3＋, and the other was from 5d level of Tb^3＋to 4f^7 level of Gd^3＋. The new findings would be beneficial for the study of Tb^3＋-doped scintillating phosphate glass.
