The solubility of 5-methyl-2-pyrazinecarboxylic acid (MPCA) in 12 pure solvents within the temperature range from 273.15 to 313.15 K under 101.3 kPa was determined and correlated by some thermodynamic models including the modified Apelblat equation, lambda h equation, and Wilson model. The results increased with the rising temperature, and it decreased with the following sequence (at a certain temperature): 1,4-dioxane > ethanol > n-propanol > 1-butanol > methanol > isopropanol > acetone > 2-butanone > ethyl acetate > water > acetonitrile > toluene. Moreover, the solvent effect and solute-solvent intermolecular interaction were analyzed during the dissolution process of MPCA in pure organic solvents. The maximum values of the relative average deviation and root-mean-square deviation were no more than 1.67% and 3.43 X 10(-4), respectively. Furthermore, the mixing Gibbs energy, mixing enthalpy, and mixing entropy were calculated by the Wilson model as well, and the values of Delta(mix)G and Delta H-mix are all negative, while those of the Delta S-mix are all positive. The calculated results of thermodynamic properties indicate that the mixing process is not only exothermic but also entropy-driven.