In this research, a series of lanthanide complexes with a low molecular weight hindered amine have been synthesized for the first time from lanthanide chloride and bis-(2,2,6,6-tetramethyl-4-piperidinyl)-decanedioicacid (L) by simply using a solvent-free solid-state reaction. Elemental and therm analysis suggest that the component of the complexes is LnLCl(3) 2H(2)O (Ln = Y, La, Nd, Sm, Eu, Gd, Dy, Er). Infrared spectra indicate that the lanthanide ions are coordinated with oxygen atoms of the carbonyl group in ligand. Polypropylene films containing the ligand and complexes were prepared by melt blending and compression molding, and were exposed to UV irradiation before and after ethanol extraction. The measurements of carbonyl index, thermal decomposition temperature, and tensile elongation at break reveal that these complexes have comparable photostabilizing efficiency and improved extraction resistance compared to the ligand alone. This study suggests that hindered-amine lanthanide complexes can provide novel approach to the cheap and efficient light stabilizers. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 250-258, 2010