The solubilities of NH4Cl and NaCl in the mixtures of monoethylene glycol (MEG) and water were determined, respectively, in the temperature range of (278 to 353) K by a dynamic method. The NaCl NH4Cl MEG H2O system with MEG mole fraction of 0.30 on a salt-free basis was also investigated from (278 to 353) K to determine its phase equilibrium as a function of temperature and the concentration of electrolytes. The solubilities of both NH4Cl and NaCl in the MEG H2O mixtures were found to decrease with the addition of MEG and the increasing concentration of the secondary electrolyte. The results show that the increment of temperature causes a marked increase in the solubility of NH4Cl but only has a slight impact on the solubility of NaCl. The mixed-solvent electrolyte (MSE) model was applied to model solid liquid equilibrium for the system containing NaCl, NH4Cl, MEG, and H2O. Binary interaction parameters for MEG-NH4+, MEG-Na+, and Na+-NH4+ were newly determined by regressing the experimental data. The MSE model with new parameters presented very high accuracy to calculate solubilities for the NaCl NH4Cl MEG H2O system. The average absolute relative deviations (AARD) between the prediction and the experimental solubility are 0.75 and 0.88% for NH4Cl and NaCl, respectively.