We report on the dynamical structure of water in NaCl aqueous solutions as functions of temperature and concentration by a low-frequency Raman spectroscopy. The spectral profiles in the frequency range from -50 to 250 cm(-1) have been analyzed with a superposition of one Cole-Cole type relaxation mode and two damped harmonic oscillator modes. The distributions: of the characteristic frequencies of the intermolecular vibrational modes observed around 50 and 180 cm(-1) in, NaCl aqueous solutions are always wider than those in pure water. In NaCl aqueous solutions with various concentrations the spectral line width g(1) = 1/(2 pi c tau) of a central component, which corresponds to the reciprocal relaxation time, Linearly changes with temperature:from about 255 K to 300 K, while the relaxation time above 300 K holds an Arrhenius-type behavior. The slope of the spectral linewidth against temperature below 300 K decreases with increasing concentration. The distribution parameter of the relaxation time in the Cole-Cole type relaxation formula decreases with decreasing temperature and it becomes smaller with, increasing concentration.