Surface enhanced Raman scattering(SERS) from molecular water adsorbed at silver in electrolytes containing Br ions, solvents of which are mixed solutions of water and alcohol, is campared with those in aqueous solution. The enhancement is larger in mixed solutions than in aqueous solution by twice or more. The linewidth of O-H stretching band becomes narrower as the ratio of alcohol to water is increased. Especially, two kinds of peaks($3550 cm^{-1}$ and $3500 cm^{-1}$) of stretching mode appeared clearly for NaBr electrolyte in mixed solvent. The effect of $K^+$ ions is very different from that of $Na^+$ ions on lineshape and potential dependence of SERS whereas the normal Raman spectra of KBr and NaBr aqueous solutions are nearly same.