Four complexes have been prepared by reaction of rare earth nitrates with 2-acetylnaphthol-hydrazinehydrate (ANH) and phenanthroline. The complexes were characterized by IR spectra. The fluorescent properties of the europium and terbium complexes in solid and in DMSO solution were investigated and the effects of phenanthroline on the luminescent intensity of europium and terbium complexes also were studied. The results show that the europium and terbium ions formed stable complexes by coordinating to the nitrogen atoms and oxygen atoms of the ligands and the nitrates. And the complexes exhibited maximum fluorescence emissions in blue region.