The phase equilibria of the Mg-Pb-Zn ternary system were investigated using electron probe micro-analysis (EPMA), back scattered electron (BSE) imaging and X-ray diffraction (XRD) methods. Three isothermal sections of the Mg-Pb-Zn ternary system at 200 degrees C, 300 degrees C and 400 C were experimentally established. The phase equilibria of Mg-Pb binary and Mg-Pb-Zn ternary system were thermodynamically assessed by using CALPHAD (Calculation of Phase Diagrams) method on the basis of the presently determined experimental data. A consistent set of thermodynamic parameters has been derived for describing the Gibbs free energies of each solution phase and intermetallic compound in the Mg-Pb and Mg-Pb-Zn systems. The calculated phase diagrams and thermodynamic properties in the Mg-Pb and Mg-Pb-Zn systems are in good agreement with experimental data. (C) 2016 Elsevier B.V. All rights reserved.