Gas-liquid-solid　three-phase　fluidized　beds　have　been　widely　used　in　the　fields　of　both　chemical　technology　and　biotechnology.　Axial　distribution　of　the　solid　particles　in　fluidized　beds　may　affect　the　hydrodynamics　of　the　beds,　which　in　turn　affects　the　conversion　rate　and　the　mass　and　heat　transfer　inside　the　beds.　An　overview　of　the　current　state　of　knowledge　on　modeling　the　axial　distribution　of　solid　particles　in　fluidized　beds　was　presented　in　this　paper.　Emphasis　was　placed　on　a　discussion　of　the　sedimentation-dispersion　model　because　it　is　often　adopted　to　describe　the　axial　distribution　of　solid　particles　for　single-　or　multi-component　in　the　beds.　In　addition,　models　taking　account　of　entrainment　or　shedding　in　the　wake　of　bubbles　was　also　presented.