The effects of the post heat treatment for electroplating on the adhesion of Ni or Ni/Cu coating were mainly studied in this thesis. The XRD results showed that the diffusion layer was formed between the coating and the base metal after the diffusion treatment, which was mainly consisted of solid solusion or intermetallic compound, such as Ni 3Ti, NiTi and NiTi 2 There was no direct relationship between the improvement of plating adhesion and the thickness of diffusion layer due to the formation of metallic bonds between the coating and the base metal. The metallic bonds can be easily formed and the plating adhesion can be improved when the integrality of the nonmetallic film, such as oxide film, was destroyed by the solid sulusion and metallic compound in thc diffusion layer. The microcosmic clearance between the plating layer and matrix did not increase due to the heat treatment