A novel β-diketone 1-(4-aminophenyl)-4,4,4-trifluorobutane-1,3-dione(p-NBFA) was synthesized by Classical claisen condensation reaction. With p-NBFA as the first ligand and 1,10-phenanthroline(phen) as the secondary ligand, two new rare earth Eu(Ⅲ), Tb(Ⅲ) ternary complexes were prepared. Elemental analysis demonstrated that the compositions of the complexes were Eu(p-NBFA)3phen and Tb(p-NBFA)3phen. IR spectra indicated that rare earth ions were coordinated with oxygen atoms of the first ligand and two nitrogen atoms of the secondary ligand. UV spectra showed that the main absorption was from the first ligand in the complexes, the secondary ligand was acted as the synergistic coordination. Fluorescence spectra demonstrated that the emission intensity of Eu(p-NBFA)3phen was obviously stronger than that of Tb(p-NBFA)3phen. Further investigation showed that the emission intensity was influenced by the matching situation of energy level between the triplet state of ligand and the emission energy of rare earth ion. In Tb(p-NBFA)3phen, due to that the triplet state energy level of p-NBFA was too near to the energy level of 5D4, then the energy transfered back to the ligand, most of the excitation energy was consumed, so the terbium complex showed lower luminescence intensity and competitive luminescence of p-NBFA also appeared. In Eu(p-NBFA)3phen, the energy level difference was well matched and the emission of europium complex was characteristic and high.