A combinatorial approach has been utilized for researching the luminescence of rare-earth ions complexes (RE(DBM)3·Phen, RE=Dy3+, La3+, Gd3+, Sm3+, Y3+) sensitized Eu3+ complex in PMMA matrix. The results show that the La3+ complex has the maximum sensitization efficiency among these sensitization ions. The luminescent intensities increase as the Eu content increase in PMMA matrix. The La3+ complex exhibits higher sensitization efficiency at lower Eu content in PMMA matrix. At a content of 5% Eu complex, the maximum sensitization efficiency of La3+ is more than 20 times.