Hard　carbon　anodes　(HCAs)　possessing　exceptional　sodium　storage　properties　undoubtedly　represents　one　of　the　optimal　choices　for　practicable　sodium-ion　batteries　(SIBs).　In　further　improving　and　optimizing　the　performance　of　SIBs,　a　systematic　investigation　of　HCA　structures　in　particular　the　microstructures　of　solid　electrolyte　interface　(SEI)　formed　on　the　HCA　surface　and　the　sodium　storage　models　is　definitely　needed.　In　this　paper,　the　recent　research　progress　in　SIBs　hard　carbon　anodes,　the　formed　SEIs,　the　degradation　mechanisms　and　the　mitigation　strategies　for　reducing　degradation　is　comprehensively　reviewed　from　three　primary　aspects:　(1)　the　fundamental　understanding　of　the　sodium　storage　mechanisms　of　hard　carbon　in　terms　of　the　distinct　modes　including　sodium　adsorption/insertion,　and　pore　filling　within　hard　carbon　materials;　(2)　based　on　the　design,　synthesis,　theoretical　characterization　and　performance　optimization　of　new　materials,　the　understanding　of　the　structure-performance　relationship　of　hard　carbon　anodes　provides　a　potential　approach　for　the　design　of　high-performance　SIBs　anodes;　and　(3)　the　challenges　related　to　the　degradation　of　hard　carbon　anode　and　the　formed　SEI　between　its　surface,　and　the　mitigation　strategies　for　reducing　the　degradation.　It　is　anticipated　that　this　review　could　provide　valuable　guidance　for　future　research　endeavors　and　commercial　development　related　to　hard　carbon　anodes　for　SIBs.　©　2024　Elsevier　Ltd