Solubility of disodium 5'-guanylate in water + ethanol binary solvent mixtures was determined by a gravimetric method in the temperature range from 283.15K to 323.15 K, pH range from 8 to 10 and at different water/ethanol mole ratios. The effects of pH, temperature and water/ethanol mole ratio on the solubility were investigated in detail. The modified Apelblat model and the combined nearly ideal binary solvent (CNIBS)/Redlich-Kister model were selected to correlate the experimental data. The results showed that the experimental data was satisfactorily correlated by the (CNIBS)/Redlich-Kister model, but for the modified Apelblat model, the correlation was not so satisfactory in some cases. (C) 2011 Elsevier B.V. All rights reserved.