Abstract: Ni/SiO₂ catalysts were prepared by impregnation method and treated by glow discharge plasma. The Ni/SiO₂ catalysts were characterized by CO₂-TPD and H₂-TPR; the effects of plasma treatment on the performances of Ni/SiO₂ in adsorption, reduction, and catalytic methanation of CO₂ were investigated. The results showed that the plasma treatment can remarkably improve the dispersion of active components and enhance the reactivity of Ni/SiO₂ catalyst. The catalytic performance of Ni/SiO₂ in CO₂ methanation is also enhanced by the plasma treatment; the conversion of CO₂ and the space time yield of CH₄ over the plasma modified catalyst are higher than those over the Ni/SiO₂ catalyst obtained through conventional impregnation and calcination method.