Co-based catalysts were developed for the production of high-calorie synthetic natural gas. The Co reduction in Al2O3- and SiO2-supported catalysts prepared with different Co loading, and their catalytic properties for highcalorie methanation were investigated. The CO conversion of the Co/SiO2 catalysts was superior to that of the Co/ Al2O3 with the same Co loading, due to their better reducibility at 400 °C. The activities of both the Al2O3 and SiO2- supported catalysts increased with Co loading, while the growth of hydrocarbon chains decreased as the Co loading increased. As the reduction temperature increased, crystallite size of Co increased in 10 Co/SiO2, resulting in decrease of CO conversion and increase of C2+ selectivity. The highest CO conversion (98.7%) was obtained over 10Co/SiO2 reduced at 400 °C. Moreover, the heating value of the product gas (10,405 kcal/Nm3) exceeded the standard heating value without requiring a high reduction temperature (700 °C) or a noble metal (Ru).