Isobaric vapor-liquid equilibrium (VLE) for the system methyltrichlorosilane-dimethyldichlorosilane-benzene and that of the three binary systems were measured with a new pump-ebulliometer at the pressure of 101.325 kPa. These binary compositions of the equilibrium vapor were calculated according to the Q function of molar excess Gibbs energy by the indirect method and the resulted VLE data agreed well with the thermodynamic consistency. Moreover, the experimental data were correlated with the Wilson, NRTL, Margules and van Laar equations by means of the least-squares fit, the acquired optimal interaction parameters were fitted to experimental vapor-liquid equilibrium data for binary systems. The binary parameters of Wilson equation were also used to calculate the bubble point temperature and the vapor phase composition for the ternary mixtures without any additional adjustment. The predicted vapor-liquid equilibrium for the ternary system accorded well with the experimental results. The separation factor of methyltrichlorosilane against dimethyldichlorosilane in benzene was also reported. The VLE of binary and multilateral systems provided essential theory for the production of the halogenated silane. (c) 2006 Elsevier B.V. All rights reserved.