Abstract: The multi-element Ni-Cr-Mo-Nb surface alloying has been studied by means of Double Glow Plasma Surface Alloying Technique. The results show that the highly alloyed gradient Ni-base surface alloying layer can be formed by double glow multi-element Ni-Cr-Mo-Nb plasma sauce alloying. The composition demising phenomenon, which exist in plasma Ni-Cr-Mo-Nb scarce alloying Process, has been discussed based on alloying element diffusion.