Phase equilibria in the ternary system KCl-SrCl2-H2O at 25 ℃ was studied by using the isothermal method. Density and refractive index of the solution were also determined. The phase diagram was plotted according to the experimental data. In the equilibrium phase diagram of KCl-SrCl2-H2O, there is one invariant point, two univariant curves and two regions of crystallization: KCl and SrCl2·6H2O. In the invariant point, the composition of the liquid phase (mass fraction, wB) was wKCl 7.22%, wSrCl232.31%, the solid phase was KCl and SrCl2·6H2O. Neither double salts nor solid solutions between KCl and SrCl2·6H2O were found, and dehydration of SrCl2·6H2O didn′t occur in the system. The system is a simple eutectic type.