Single-crystal polarized Raman spectra (60-4000 cm(-1) at 3 <= T <= 295 K) were measured for chiral L- and racemic DL-serine, alpha-amino-beta-hydroxypropionic acid, (NH3)+CH(CH2OH)(COO)(-). The Raman spectra of DL-serine do not show any striking changes with temperature or on storage. In contrast to that, the dynamical properties Of L-Serine change at about 140 K. These changes can be interpreted as the reorientation of the side chain -CH2OH fragments of the zwitterions with respect to the backbone C-C bonds, resulting in the positional disorder of the O-H center dot center dot center dot O intermolecular H-bonds. The redistribution in the intensities of the Raman spectra of the crystals Of L-serine stored for a long time (about a year) indicates the changes in the orientation of the molecular fragments in the direction normal to the axes of the head-to-tail chains. The difference in the thermodynamic functions Of L- and DL-serine reported previously [Drebushchak, V. A.; Kovalevskaya, Yu. A.; Paukov, I. E.; Boldyreva, E. V. J. Therm. Anal. Calorim. 2007, 89 (2), 649-654] is explained by the difference in the spectra of external vibrations of the crystals.