Four ligands 1,10-phenanthroline-5,6-bis(N,N-dibenzyl-1'-oxopropylamide) (La) 1,10-phenanthroline-5,6-bis(N-methyl-N-benzyl-1'-oxopropylamide) (Lb) 1,10-phenanthroline-5,6-bis(N-benzyl-1'-oxopropylamide) (Lc) and 1,10-phenanthroline-5,6-bis(N,N-diethyl-1'-oxopropylamide) (Ld), and their lanthanide(III) (La and Eu) complexes were synthesized. The complexes were characterized by elemental analysis, IR, fluorescence spectroscopy and conductivity. The lanthanide atoms are coordinated by O atoms from C=O, Ar-O -C and N atoms from phen With the difference of the ligands, the fluorescent intensities of the Eu(III) complexes vary regularly in the THF solution. Some factors that influence the fluorescent intensity were discussed.