The crystalline lanthanide complexes (except Ce and Pm) with proline were synthesized. The general formula of [Ln(Pro)2(H2O)4]3(ClO4)3of the complexes were obtained from chemical analysis, elemental analysis, TG-DTA analysis and electrical conductivity. Infrared spectra reveal a considerable shift of the symmetric co2stretching mode from lower to higher energies in the lanthanide complexes and a decrease of Δv(Δv=vcoo-as-vcoo-s) from 212 cm−1in proline to about 167 cm−1in the complexes. The peak mean 405cm−1in the Raman spectra varies with the total orbital angular smomentum of the lanthanide ions in the ground states, exhibiting a profile of an “inclined w”. These spectral features in the IR and Raman spectra were regarded as strong evidences of Ln-O bonding. The peak near 405cm1was assigned as the Ln-O stretch modes.