Abstract: A series of Ni₂P/Ce-Al₂O₃ catalysts were prepared by temperature-programmed reduction method, and the influence of Ni₂P loading on the catalyst structure and naphthalene hydrogenation saturation performance was investigated. The results show that the specific surface area, the Ni₂P particle size and the active site number of the as-synthesized catalysts are greatly affected by Ni₂P loading, which is derived from the variable interaction between active component Ni₂P and the support Ce-Al₂O₃. When the Ni₂P loading is 17% (mass ratio), the catalyst possesses a large specific surface area (40 m²/g), a small Ni₂P particle size (26.3 nm), and the maximum number of active sites (26.7 μmol/g). Meanwhile, the conversion rate of naphthalene and the selectivity of decalin reach to 95% and 76%, respectively, and the activity stability of the catalyst is good, which is mainly attributed to the large specific surface area and high number of active sites of the catalyst providing more sites for the reaction.