The ion-based electrolyte Wilson model is combined with the segment-based polymer Wilson model to represent the excess Gibbs energy of aqueous polymer-electrolyte solutions. The model provides a versatile and flexible thermodynamic framework for both correlating and predicting the phase equilibrium of electrolyte solutions, polymer solutions and complex systems containing both electrolytes and polymers. The utility of the model is demonstrated with successful representation of vapor-liquid equilibrium of several PEG or PPG-salt-H2O systems at different polymer molecular weights.