The　effects　of　Si　addition　to　Fe　on　the　formation　and　growth　of　intermetallic　compounds　(IMC)　in　Fe/Al　composites　were　studied　by　Scanning　electron　microscopy　(SEM),　Energy　Dispersive　Spectroscopy　(EDS)　and　electron　backscatter　diffraction　(EBSD)　techniques.　The　results　showed　that:　when　annealing　time　was　1　h,　the　critical　IMC　formation　temperature　of　Pure　Al/Pure　Fe,　Pure　Al/Fe+0.82Si,　Al+0.88Si/Pure　Fe　and　Al+0.88Si/Fe+0.82Si　were　440　degrees　C,　480　degrees　C,　520　degrees　C　and　620　degrees　C,　respectively.　The　major　IMC　phase　formed　in　the　four　composites　after　heat　treatments　at　640　degrees　C/1h　and　640　degrees　C/24h　was　the　eta　phase　(Fe2Al5),　and　a　large　number　of　theta　phase　(Fe4Al13)　particles　were　present　in　the　eta　phase　for　the　Pure　Al/Pure　Fe　sample.　When　Si　element　was　added　to　Fe　and　Al,　Fe3Al2Si3　phase　and　FeAl2Si　phase　were　observed　in　the　eta　phase.　The　thickness　of　the　formed　IMC　layer　in　the　four　composites　after　heat　treatment　at　640　degrees　C/1h　was　in　the　order:　Pure　Al/Pure　Fe　approximate　to　Pure　Al/Fe+0.88Si　＞　Al+0.888Si/Pure　Fe　approximate　to　Al+0.888Si/Fe+0.88Si.　The　growth　activation　energies　of　the　IMC　layer　in　the　Pure　Al/Pure　Fe,　Pure　Al/Fe+0.82Si,　Al+0.88Si/Pure　Fe,　Al+0.88Si/Fe+0.82Si　samples　were　76.1　kJ/mol,　276　kJ/mol,　349　kJ/mol　and　519.6　kJ/mol,　respectively.　The　effect　of　Si　atoms　on　the　formation　of　IMC　was　mainly　by　the　interfacial　enrichment　mechanism　and　the　new　phase　inhibition　mechanism　of　FexAlySiz.　The　enrichment　of　Si　at　the　interface　of　Al　and　Fe　increased　the　growth　activation　energy　and　reduce　the　growth　rate　of　IMC　layer　thickness.　The　formation　of　new　FexAlySiz　phase　can　inhibit　the　rapid　growth　of　IMC　phase　along　the　C　axis.