A nitrogen-containing nickel catalyst adapted for catalyzing partial and selective hydrogenation of natural oils is disclosed, which comprises nickel and such an amount of a nitrogen-containing basic compound which is equivalent to from about 5 to about 40 atoms of nitrogen per 100 atoms of nickel.The catalyst is effective in catalyzing the partial hydrogenation of natural oils in such a manner that poly-unsaturated compounds are selectively hydrogenated and the formation of saturated compounds, transisomers, and conjugated dienes is limited and liquid hydrogenation products can be obtained. The catalyst is prepared by treating a nickel catalyst with the nitrogen-containing compound at elevated temperatures optionally under hydrogen.