Ag-Ru/CeO2　catalysts　were　prepared　by　co-precipitation　(CP),　modified　deposition　precipitation　(MDP),　and　incipient-wetness　impregnation　(IP).　The　obtained　catalysts　were　characterized　by　N-2　physisorption,　X-ray　diffraction　(XRD),　H-2　temperature-programmed　reduction　(H-2-TPR),　and　temperature-programmed　desorption　of　nitrogen　(N-2-TPD).　The　results　showed　that　the　ammonia　synthesis　activity　of　the　Ag-Ru/CeO2　catalyst　prepared　by　incipient-wetness　impregnation　was　9.4%　at　10　MPa,　10000　h(-1)　and　400　degrees　C,　which　was　higher　than　that　obtained　by　other　methods.　There　were　obvious　differences　in　the　reduction　property　of　Ru/CeO2　and　in　the　nitrogen　dissociation　behavior　among　the　catalysts　prepared　by　different　methods.　Catalyst　activity　for　the　catalyst　prepared　by　incipient-wetness　impregnation　improved　greatly　at　a　low　reaction　temperature.　The　high　catalytic　activity　was　due　to　the　easier　reduction　of　Ag-Ru/CeO2　and　the　higher　amount　of　dissociation　of　chemisorbed　nitrogen.