Raman spectra of a saturated aqueous solution of sodium nitrate (NaNO3/H2O) in the region of the totally symmetric vibration v(1)(A) of the NO3- anion has been studied. The high-voltage pulsed electric discharge effect (HPED activation) on the molecular relaxation in NaNO3/H2O has been investigated. The temperature dependences of the width and frequency of the corresponding spectral line are examined. The transition of NaNO3/H2O from the normal state to the activated state under HPED effect is observed. The activated state of NaNO3/H2O is nonequilibrium and metastable. (C) 2003 Elsevier B.V. All rights reserved.