Extensive study of hydration of alkaline and alkaline earth cations in aqueous solutions of perchlorate salts has been performed using Raman spectral technique. The Raman lineshape and position of of thev1(A1) vibrational mode of perchlorate anion have been measured over a wide range of concentrations from highly dilute to the near saturated solutions. The structure of the first coordination sphere has been established for each studied cation using frequency shift and half-width changes of measured band. Spectral data are compared with those obtained by electrochemical measurements.