Chloride and sulfate brines are typical in the salt lakes of Qinghai China where the ions of Na+,Mg2+, Ca2+, K+, Li+ ions are normally contained.The industrial processes in salt-lake are normally under the natural conditions, which the phase equilibria dynamic are complex.The complexities of phase equilibria dynamic are caused not only by the phase equilibria change with temperature,evaporation, and fractional crystallization, but also by the complex metastable phenomena and salt-forming dynamic.The accurate representation and reliable prediction for the dynamic behaviors of phase equilibria are very important but also very difficult.In this study, salt-forming principle [1] is applied to present the salt forming behaviors [2], the symmetric electrolyte NRTL model [3] was applied to model the stable solid liquid equilibria.The model parameters include water-electrolyte and electrolyte-electrolyte binary interaction pairs were regressed from thermodynamic data of salt-water binary or ternary systems.The Gibbs free energy for homogeneous and heterogeneous nucleation was employed as new parameters for solid, which were identified from respective binary or ternary system for single or double salt respectively.The results show that the models could accurately present the stable phase diagrams, and reasonably calculate the salt forming regions.Thus it is expected to predict the limited boundary of metastable phase diagram and phase equilibria dynamic for the complex salt-water systems in nature conditions or industrial conditions.