Abstract: Nanocrystalline Ni-W-RE alloy coatings were prepared by electrodeposition and the performance and preparation technology were studied.The effects of current density,time of deposition,RE content in plating solution,pH value and temperature on the deposition rate of the coatings were studied.Surface morphology,structure,composition,corrosion resistance and oxidation resistance of composite coatings were tested by SEM,XRD,EDS and anodic polarization curves etc.The results show that the optimized preparation conditions of composite coatings were current density 9.5 A·dm-2,pH=7,time of electrodeposition 70 min,temperature of the solution 50 ℃,NdCl3 content in the solution 4.5 g·L-1 and Ce(SO4)2 content 3 g·L-1.The surface grains of the alloy coatings arranged densely,uniformly and without cracks after adding the RE elements of Nd and Ce.And the high temperature oxidation resistance and corrosion resistance of Ni-W-Nd alloy coatings were only a littre different from those of the hard chromium plating.