Four complexes of Eu,3+, and Tb,3+, ions with 2,2'-dipyridyl (Dipy) and 1,10-phenanthroline (Phen) were synthesized in the absolute ethanol solutions,and the fluorescence properties of the complexes were studied.With respect to Dipy,Phen has higher electron density in the conjugated system with the result of a higher orbital overlap and consequently an easier transfer of energy to the rare earth ions,which make the fluorescence intensity of Phen complexes be stronger than that of Dipy complexes.Moreover,the high resolution emission spectra of Eu,3+, measured at 77K indicate that the symmetry of Eu,3+, sites in Eu(Phen) ,2,Cl,3,·2H,2,O and Eu(Dipy) ,2,Cl,3,·2H,2,O is C,1, or C,2, or C,S,.