Abstract：Cu/Si gradient layer was made by ihrigizing, on basal body Cu, using the silicon electrodeposited in KCl-NaCl-NaF-SiO2 system as silicon source. The influence of preparation parameter on microstructure of Cu/Si gradient layer section was investigated. The results showed that Cu/Si gradient layer is made of surface layer, intermediate layer and transitional layer with different microstructure, and the microstructure of surface layer and intermediate layer are respectively the equiaxed grain and the columnate crystals organization. The thickness of Cu/Si gradient layer increases with electrodiposition temperature or electrodeposition time, and at the same time,the crystal grain size in surface layers and intermediate layer all decrease. When extending electrodiposition time, the thickness of surface layer gradually increases and the thickness of intermediate layer gradually decreases. In the Cu/Si gradient layer, the phase constitute of surface layer is made of one or two of (Cu), К, γ, η and ε, and the phase constitute of transitional layer is (Cu).