The NiO catalyst was prepared from Ni-Al precursor (NiO content 10-40 wt.%, grain size 2.25-8 mm) and used for methanization of CO and CO2 at 220-270 degrees C in a gradientless laboratory reactor. The catalyst activity increased with the increasing NiO content but decreased with the increasing grain size of the catalyst. The catalyst containing 30% of NiO and consisting of grains sized 3-4 mm was more active than the common RANG-19 and RANG-19PR catalysts by 30-40%.