The effect of the type of alkali metal cation and salt concentration on ion-ion and ion-polyether interactions has been examined for poly(ethylene glycol) (PEG)-MSCN (M Li, Na, K) electrolytes by means of impedance spectroscopy, DSC, theological, and FT-IR techniques. Studies were performed in wide salt (from 10(-5) to 5 mol/kg PEG) and temperature (from 20 to 90 degreesC) ranges. It is shown that for low salt concentrations of approximately up to 10(-3) mol/kg PEG and for high salt concentrations (>1 mol/kg PEG), conductivities measured for LiSCN-doped electrolytes are higher than those for other systems. In the intermediate salt concentration range, the conductivities of all electrolytes studied are comparable.