Milisecond high density electrical pulse was used to age one of the typical IC lead frame materials Cu-2.5Fe-0.03P-0.1Zn copper alloy. The effects of electrical pulse aging on the microstructures, electrical conductivity and microhardness of this alloy were systematically investigated. The experimental results shown that the alloy phase precipitated in Cu-2.5Fe-0.03P-0.1Zn copper alloy during electrical pulse aging could be controlled to the order of nano-size and the ideal match of electrical conductivity and microhardness could be achieved in the condition of optimized parameters of electrical pulse. The electrical conductivity of the alloy was kept at above 60%IACS while the microhardness reached to HV115. A preliminary theoretical analysis was made to explain the unique action of electrical pulse.