The　ammonia　decomposition　for　the　production　of　carbon-free　hydrogen　has　triggered　great　attention　yet　still　remains　challenging　due　to　its　sluggish　kinetics,　posting　the　importance　of　precise　design　of　efficient　catalysts　for　ammonia　decomposition　under　low　temperatures.　Constructing　the　metal-support　interaction　and　interface　is　one　of　the　most　important　strategies　for　promoting　catalysts.　In　this　work,　by　coating　ceria　onto　the　Ni　nanoparticles　(NPs),　we　discover　that　the　Ni-CeO2　interfaces　create　an　exceptional　effect　to　enhance　the　catalytic　decomposition　of　ammonia　by　over　10　folds,　compared　with　the　pristine　Ni.　The　kinetic　analysis　demonstrates　that　the　recombinative　N2　desorption　is　the　rate-determining　step　(RDS)　and　the　Ni-CeO2　interface　greatly　increases　the　RDS.　Based　on　these　understandings,　a　strategy　to　fabricate　the　Ni/CeO2　catalyst　with　abundant　Ni-Ce-O　interfaces　via　one-pot　sol-gel　method　was　employed　(hereafter　denoted　to　s-Ni/CeO2).　The　s-Ni/CeO2　catalyst　shows　a　high　activity　for　ammonia　decomposition,　achieving　a　H2　formation　rate　of　10.5　mmol　gcat-1　min-1　at　550　degrees　C.　Combined　with　a　series　of　characterizations,　the　relationship　between　the　catalyst　structure　and　the　performance　was　investigated　for　further　understanding　the　effect　of　metal-oxide　interfaces.