The present investigation is aimed at deriving a set of self-consistent thermodynamic functions for the AgCl-CoCl2-InCl3-KCl quaternary system within the framework of the CALPHAD approach. All the previous reported thermodynamic parameters for the binary subsystems were initially reviewed and adopted, and critical thermodynamic evaluations and optimizations were later performed on the unavailable AgCl-KCl and InCl3-KCl systems in terms of the required phase equilibria and thermochemical data from experimental measurements and theoretical predictions (First-principles method and empirical equation). The Modified Quasi-Chemical model were applied to describing the molten salt phase, while all the intermediate phases were treated as the stoichiometric compounds due to no observation of the homogeneity composition range. Various phase equilibria and thermodynamic properties in the ternary and quaternary systems could be facilely calculated based upon the ultimate thermodynamic database established in this case, which will support beneficial instructions in the related industrial processes. (C) 2015 Elsevier B.V. All rights reserved.