Abstract: Computer simulations are employed to research the adsorption behavior of UO₂²⁺ in hydroxyapatite (HA), which is used as vitro model of bone. The influence of several chelating agents is also investigated. Results show that, the adsorption equilibrium of UO₂²⁺ in HA is achieved in 15min, changes in the particle morphology of HA are not obvious and the adsorption process follow pseudo-second-order kinetics equation. Both of EDTA and DTPA can chelate with UO₂²⁺, which induce a considerable desorption of UO₂²⁺ from HA, however, also some degree of damage in the bone inorganic surface simultaneously. Citric acid has a strong promotive effect on desorption of UO₂²⁺ from the HA, but high concentration citric acid is unsuitable used as chelating agent, because it will remarkably change the particles morphology of HA. Ascorbic acid has no effect on desorption of UO₂²⁺ from HA, and NTA can lead to an increase of adsorption of UO₂²⁺ on HA.