The stable phase equilibrium of the two ternary systems LiCl-MgCl2-H2O and SrCl2-MgCl2-H2O at 333 K were researched by using the isothermal dissolution equilibrium method. The solubilities of salts in the equilibrium solution were determined, and the equilibrium solids were also investigated by using the Schreinemaker method. In the ternary system LiCl-MgCl2-H2O at 333 K, the phase diagram of the system is composed of two invariant points, three univariate curves, and three crystallization regions corresponding to MgCl2 center dot 45H(2)O, LiCl center dot H2O, and double salt LiCl center dot MgCl2 center dot 7H(2)O, no solid solution was found in the phase diagram. In the ternary system SrCl2-MgCl2 - H2O at 333 K, there are two invariant points, three univariate solubility curves, and three crystallization areas corresponding to SrCl2 center dot 6H(2)O, SrCl2 center dot 2H(2)O, and MgCl2 center dot 6H(2)O; this system belongs to hydrate type IL and neither double salts nor solid solutions were formed.