DC and ac conductivities of AgI(α-Fe2O3) composite electrolytes have been measured. It is found that the Morin transition temperature of α-Fe2O3 is dereased by the addition of AgI. The results of M?ssbauer spectra and susceptibility are qualitatively coincide with electrical measurement. Phase transition temperature of AgI from α to βphase is also significantly lowered by the existance of α-Fe2O3. The experiments have been shown that phase transition temperature of the two phases in composite electrolyte were influenced each other.