A　series　of　CeO2-La2O3　supported　ruthenium　catalysts　were　prepared　by　co-precipitation　method　and　the　as-obtained　samples　were　characterized　by　N-2　physisorption,　X-ray　diffraction,　CO　chemisorption,　H-2-TPR,　H-2-TPD　and　XPS.　The　activity　test　shows　that　ammonia　concentration　of　the　catalyst　with　10%　La　is　13.9%　at　10　MPa,　10,000　h(-1),　450　A　degrees　C,　which　is　17%　higher　than　that　of　Ru/CeO2.　La　doping　can　improve　the　activity　of　Ru-ceria　catalyst　for　ammonia　synthesis　by　facilitating　the　reduction　of　oxygen　which　subsists　in　the　cerium　oxide　surface.　In　addition,　it　can　be　realized　that　the　test　of　catalyst　stability　proves　the　stability　performance　of　Ru/CeO2-La2O3　catalyst　within　the　reaction　time　of　55　h.