RE(ClO4)3 x L5 x C2H5OH(RE=Gd, Tb, Dy, Tm, Yb; L = C6H5COCH2SOCH3) complexes were synthesized. The composion of the complexes was determined by elemental analysis, coordination titration, molar conductivities, and TGA studies. The ligand and coordination compounds were studied by means of IR spectra, 1H NMR, and the Tb(II) coordination compound was studied by means of phosphorescence spectra, and fluorescence excitation and emission spectra. Each energy level of Tb3+ was calculated according to the fluorescent emission spectra results.