The effect of Si addition and heat treatment on the Al-5wt.%Fe alloy has been investigated by OM, SEM-EDS and XRD. The results show that the Si plays a significant role in refining the primary Al3 Fe phase. It was found that the addition of 3.0wt.% Si made the alloy present the finest and well-distributed primary Al3 Fe phase, but the Al3 Fe phase almost disappeared when 5wt.% Si was added. With further increase in the Si content, some Fe-rich phases appeared in the inter-grains and coarsened. In addition, the heat treatments exert a significant impact on the microstructural evolution of the Al-5wt.%Fe-5wt.%Si alloy. After heat treatment for 28 hours at 590 oC, the coarse platelet or blocky Fe-rich phase in Al-5wt.%Fe-5wt.%Si alloys was granulated; the phase transformation from metastable platelet Al3 FeSi and blocky Al8Fe2 Si to stable Al5 FeSi had occurred. With the extension of heat treatment, the Si phase coarsened gradually. The results of Si addition and heat treatment on the Al-5wt.% Fe alloy has been investigated by OM, SEM-EDS and XRD. The results show that the Si plays a significant role in refining the primary Al3Fe phase. It was found that the addition of 3.0 wt.% Si made the alloy present the fine and well-distributed primary Al3 Fe phase, but the Al3 Fe phase almost disappeared when 5 wt.% Si was added. With further increase in the Si content, some Fe- In addition, the heat treatments exert a significant impact on the microstructural evolution of the Al-5 wt.% Fe-5 wt.% Si alloy. After heat treatment for 28 hours at 590 oC, the coarse platelet or blocky Fe-rich phase in Al-5wt.% Fe-5wt.% Si alloys was granulated; the phase transformation from metastable platelet Al3FeSi and blocky Al8Fe2Si to stable Al5FeSi occurred occurred. With the extension of heat treatment , the Si phase coarsened gradually.