The Fe-Sm binary alloy ribbons were prepared by melt spinning technique. The prepared alloys with Sm 8.7 and 12.7 at% were mainly composed of TbCu₇ metastable phase. In addition, α-Fe in Sm 8.7 at% and Fe₂Sm in Sm 12.7 at% alloy were also observed. In contrast to them, the alloy with Sm 27.5 at% has an amorphous phase. After mechanical grinding (MG) for 72 ks under N₂ atmosphere, the alloys with Sm 8.7 and 12.7 at% showed the phase transition to the metastable state coexisting of α-Fe and Fe-Sm amorphous phase. On the other hand, the alloy with Sm 27.5 at% showed the crystallization after the MG from amorphous phase to Fe-Sm-O phase. The MGed alloys with Sm 8.7 and 12.7 at% were heated up to 1027 K. After the heating, the alloy with Sm 8.7 at% was composed of α-Fe, FeN, Fe-Sm-N and Fe₃O₄. On the other hand, the metastable phase was still sustained in the alloy with Sm 12.7 at%.