A vacuum infiltration process has been developed to fabricate copper matrix composites reinforced with 50 vol.-%Si powers and 0-10 wt-%Fe additive. In this study, the powder compacts were prepared using well mixed Si and Fe powders and were then packed in quartz tubes. Then pure copper was used to infiltrate these compacts. The results show that the wettability, the infiltration rate, the thermal conductivity, and the density are all promoted when the Cu/Sip composites are added to 5-10 wt-%Fe. In addition, the coefficient of thermal expansion (CTE) of the Fe containing composite is lower than that of the composites without Fe additive. From the X-ray diffraction analysis and the differential thermal analysis, it can be seen that Fe additive also can generate the FeSi2 compound and reduce the Cu3Si brittle compound formation in the Cu/Si interface.