Sodium　metal　anode　(SMA)　is　one　of　the　most　favored　choices　for　the　next-generation　rechargeable　battery　technologies　owing　to　its　low　cost　and　natural　abundance.　However,　the　poor　reversibility　resulted　from　dendrite　growth　and　formation　of　unstable　solid　electrolyte　interphase　has　significantly　hindered　the　practical　application　of　SMAs.　Herein,　we　report　that　a　nucleation　buffer　layer　comprising　elaborately　designed　core-shell　C@Sb　nanoparticles　(NPs)　enables　the　homogeneous　electrochemical　deposition　of　sodium　metal　for　long-term　cycling.　These　cpsb　NPs　can　increase　active　sites　for　initial　sodium　nucleation　through　Sb-Na　alloy　cores　and　keep　these　cores　stable　through　carbon　shells.　The　assembled　cells　with　this　nucleation　layer　can　deliver　continuously　repeated　sodium　plating/stripping　cycles　for　nearly　6000　h　at　a　high　areal　capacity　of　4　mA　h　cm(-2)　with　an　average　Coulombic　efficiency　99.7%.　This　ingenious　structure　design　of　alloy-based　nucleation　agent　opens　up　a　promising　avenue　to　stabilize　sodium　metal　with　targeted　properties.