Deuterated Eu(III) complexes of tris-(hexafluoroacetylacetonato)europium(III) dehydrates (Eu(hfa-H)3(H2O)2), tris-(hexafluoroacetylacetonato)europium(III) bis(triphenylphospine oxide) (Eu(hfa-H)3(TPPO)2), tris(hexafluoroacetylacetonato) Eu(III) 1,1'-biphenyl-2,2'-diylbis (diphenylphosphine oxide) (Eu(hfa-H)3(BIPHEPO)) were prepd. by the exchange reaction via keto-enol tautomerism of the Eu(III) complexes with CD3OD. The emission quantum yields of the deuterated Eu(III) complexes were higher than those of corresponding nondeuterated Eu(III) complexes. The lasing properties of Eu(III) complexes in polymer thin film were measured by photo-pumping of Nd: YAG laser (355 nm). Percentages of ASE components in whole emission were increased by deuteration of the Eu(III) complexes.