The phase equilibrium data for the ternary systems isobutyl acetate + {ethanol or methanol} + water were determined at temperatures of 303.15 and 323.15 K, and pressure of 101.3 kPa. Both Hand and Bachman methods were used to evaluate the validity of the experimental data in the present work. In addition, the nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) models were applied to fit the experimental tie-line data, and the binary interaction parameters of the thermodynamic models were fitted. The root-mean-square devation values obtained for the NRTL and UNIQUAC activity coefficient models are less than 0.0081, which indicates that the correlated results agree with the experimental data. Moreover, the distribution coefficients and selectivities were determined and discussed.