Liquid liquid equilibrium (LLE) for ternary systems water + acetic acid + m-xylene and water + acetic acid + o-xylene were measured at (303.2 to 343.2) K and under atmospheric pressure. The consistency of the experimental tie-line data was checked by both the Othmer-Tobias and the Hand equations as well as verified by comparison with the literature data. Both the nonrandom two-liquid (NRTL) and universal quasichemical activity coefficient (UNIQUAC) models were adopted to correlate the measured LLE data, and the binary interaction parameters were obtained by data-fitting. The predicted LLE data by using the obtained model parameters show good consistency with the literature data. It indicates the obtained binary NRTL and UNIQUAC model interaction parameters could be used in the calculation of LLE for the ternary systems water + acetic acid + m-xylene and water + acetic acid + o-xylene as well as for the design, simulation, and optimization of the related separation process.