Isobaric vapor-liquid equilibria (VLE) were measured for the binary system acetone + acetone oxime methyl ether (AOME) at 101.3 kPa. The activity coefficients were correlated satisfactorily with NRTL and Wilson models. The thermodynamic consistency of the obtained VLE data was checked by Herington method and passed the test. The results show that the correlated data of NRTL and Wilson models are both in keep with the experimental data, and the UNIFAC parameters of the new group (C=N) were determined using the obtained VLE data. The azeotrope behavior is not happen for the binary system of acetone + AOME, which can provide the basis data to design the separation process, and promote the development of new technology to produce O-methylhydroxyamine hydrochloride effectively and economically. (c) 2013 Elsevier B.V. All rights reserved.