Abstract: To understand the formation mechanism and growth behavior of Fe-Al intermetallics,the element diffusion and interfacial reactive interlayer in Fe/Al couple were studied at the different heating temperature and holding time.The interfacial structure is Fe/FeAl_x+Al/FeAl/Al at the shorter holding time,while the unstable FeAl_x and FeAl will change into the stable Fe₂Al₅ and FeAl₃ intermetallics at a longer holding time.The final interfacial structure was Fe/Fe₂Al₅+FeAl₃/Al.The growth of interfacial reactive layer follows the parabolic rule,and its rate is controlled by the diffusion rate of Fe atoms into Al side.The results are helpful to improve the bonding quality between aluminum alloys and stainless steel.