Liquid liquid equilibria data for the ternary mixture of 1-Butanol + methoxy(methoxymethoxy) methane + water were measured at atmospheric pressure and temperatures of 303.15, 323.15 and 343.15 K. The ternary system forms a type II phase diagram with two partially miscible region. The distribution coefficient (K) and separation factor (S) were calculated according to the measured tie-line data. The root-mean-square deviation (RMSD) values of NRTL and UNIQUAC models were below 0.91%, demonstrating the two activity coefficient models were successfully applied to correlate the experimental data of the ternary system. (c) 2015 Elsevier B.V. All rights reserved.