Reaction variables for methanation process were investigated using self-independently developed NiO–La2O3–MgO/Al2O3catalyst in a big lab scale reactor. The effects of reaction parameters, such as temperature, pressure, H2/CO flow ratio and space velocity on the activity of methanation catalyst were studied. 100 % CO conversion and 95 % of selectivity of methane can be achieved at 400 °C and 3 MPa with the feed ratio of H2/CO as 3.25:1 and space velocity of 12,000 h−1.The optimization reaction parameters were suggested on the basis of this work for the further development and commercialization of methanation catalyst.