The solubilities of adipic acid in cyclohexanol + cyclohexanone mixtures from 303.0 to 353.0 K and in cyclohexanone + cyclohexane mixtures from 303.0 to 378.5 K were determined using a titration and an in situ ATR-FTIR method. The averaged relative deviation between two methods at given temperatures was less than 2%. The solubility of adipic acid in cyclohexanone + cyclohexane mixtures increases with increasing mass fraction of cyclohexanone in the mixtures at given temperatures. However, the solubility of adipic acid in cyclohexanol + cyclohexanone mixtures reaches the maximum at cyclohexanone mass fraction of 0.4. The experimental data were well correlated by Apelblat equation and λ h equation. The thermodynamics functions of the dissolution process were calculated by van’t Hoff equation.