The solubilities of 2-methyl-6-acetylnaphthalene (2,6-MAN) and 2-methyl-7-acetylnaphdialene (2,7-MAN) in n-heptane, n-octane, and n-dodecane were measured, respectively, from 273.15 to 319.15K using an analytical method. On the basis of the thermodynamics theory of solid-liquid equilibrium, a model was derived to relate the solubilities with temperature. Using the least square method, the parameters of the model, the fusion enthalpies Delta H-fus and the Margules equation coefficients A(12) and A(21) of 2,6-MAN and 2,7-MAN in n-heptane, n-octane, and n-dodecane7-were obtained by regressing the experimental data. The average deviation of the model was 1.70%.