A series of phenanthroline derivatives containing quinoxaline moieties were synthesized, and their electron-transporting properties were investigated by using N,N'-di(1-naphthyl)-N,1Vdiphenyl-(1,1'-biphenyl)-N,N'-diamine (alpha-NPD) and tris(8-hydroxyquinolato)aluminum (Alq(3)) as the hole-transporting material and the emitting layer, respectively. Higher external quantum efficiency for the phenanthroline derivative than Alq3 in the electroluminescent devices at a luminance of 100 cd/m(2) was obtained.