Eu³⁺ chelates with thenoyltrifluoroacetylacetone(TTFA),Hexafluoroacetylacetone(HFA) and dibenzoyl-methide (DBM) as the ligands and PMMA doped with these chelates were synthesized,respectively. Fluorescence properties of the chelates Eu (TTFA)₃,Eu (HFA)₃,Eu (DBM)₃ in benzene solution and in PMMA matrix were investigated. It was found that the fluorescence intensity of Eu (TTFA)₃ was the topmost. The effect factors on the fluorescence intensity of complexes were analyzed. It was testified that TTFA was a good ligand of Eu³⁺ for red fluorescence emission. Finally,the dependence of Eu (TTFA)₃ doping concentrations (0.08 wt.% ～ 0.5wt.%) on the fluorescence intensity and the fluorescence lifetimes were investigated. The results showed that the fluorescence intensity and the lifetimes increased within the doping concentrations investigated. The fluorescence lifetimes were between 280～400 μs. Such fluorescing PMMA might have extensive prospect of applications in optical devices,such as polymer optical fibers,lasers,amplifiers and waveguides.