Ammonia metallurgy has the merits of a high leaching rate, good selectivity,easy purification process, so it was still studied in a great area.However, the many studies did not discover the rules of the equilibrium solubility of copper in the system of Cu-NH4Cl-H2O; It often supposed the concentration of Cu2 +, Cl-and NH3 were certain values.And the method of construction of (φ)-pH figure is not suitable in this system studying, because the potential of the system is actually a constant.