The stable ranges concerning the composition and temperature have been experimentally de-termined for the intermetallic compounds in system Fe-Cr-Mo at high-temperatures. Theisothermal section of the Fe-Cr-Mo ternary phase diagram at 1250℃ and the formation re-actions for the intermetallic compounds, which are different in part from those shown in theliterature, have been proposed. The stable concentration concerning the composition and temperature have been experimentally de-termined for the intermetallic compounds in the system Fe-Cr-Mo at high-temperatures. Theisothermal section of the Fe-Cr-Mo ternary phase diagram at 1250 ° C and the formation re- actions for the intermetallic compounds, which are different in part from those shown in the literature, have been proposed.