Abstract: With nickel nitrate and nickel acetate as nickel precursors, a series of Ni/SBA-15 catalysts were prepared by using the impregnation method and activating in air or hydrogen atmosphere. The Ni/SBA-15 catalysts were characterized with XRD, H₂-TPD, N₂ physisorption and online mass spectroscopy. Their catalytic properties were evaluated with hydrogenation of naphthalene as a model reaction. It was shown that activation in hydrogen greatly increased the Ni dispersion and catalytic activity of Ni/SBA-15 prepared with nickel nitrate, while activation in air significantly improved the sample prepared with nickel acetate. In terms of the thermal decomposition products of the catalyst precursors activated in different atmospheres, the affecting mechanism of the activation atmosphere on the Ni/SBA-15 catalysts prepared with different nickel precursors was proposed.