Abstract: CeO₂-SiO₂/Ni-W-P nano-composite films were prepared on the carbon steel surface by pulse co-deposition of Ni，W，P，nano-CeO₂ and nano-SiO₂ particles，the influence of Na₂WO₄ and NaH₂PO₂ concentrations in electrolyte on microstructures and properties of the nano-composite films was researched，and the characteristics were assessed by chemical composition,  deposition rate, microhardness and surface morphologies. The results show that when the Na₂WO₄ and NaH₂PO₂ concentrations in electrolyte are controlled at 100 and 4 g/L respectively,  the deposition rate of 25.03 μm/h and the microhardness of HV649 of the nano-composite films are obtained. The increase of the Na₂WO₄ concentration leads to refinement in the grain structure of the nano-composite films. When  improved at 160 g/L，the nano-composite films possess a clear outline of the spherical matrix metal crystallite，fine crystal size,  compact microstructure and uniform and dispersive distribution of nano-CeO₂ and nano-SiO₂ particles within the Ni-W-P matrix metal. The increase of the NaH₂PO₂ concentration in electrolyte has a little effect on the surface morphologies，but it results in a microhardness decrease of the nano-composite films.