Abstract: Humic acid (HA) was extracted from the soil by using the procedure recommeded by International Humic Substance Society (IHSS) with minor modifications. It was characterized by the element analysis and the IR spectra. Then the adsorption behaviors of U(Ⅵ) on the extracted HA were investigated by the static experimental method. The results show that more than 80% of the total U(Ⅵ) can be adsorbed by 5 mg humic acid at pH=3 from 20 mL aqueous solution of 0.84×10^-4mol/L U(Ⅵ) and the adsorption is increased with increasing pH in the range of 1-3 and decreased with increasing pH in the range of 3-10. The relationship between the concentration of U(Ⅵ) in aqueous solution and the adsorbed U(Ⅵ) is in accord with the Langmuir equation in the U(Ⅵ) concenttation range from 10^-6 to 10^-4 mol/L. In the presence of Al³⁺, Ca²⁺, Nd³⁺, Eu³⁺, CO^2-3, SO^2-4, citric acid and EDTA, the adsorption of U(Ⅵ) on the humic acid is decreased relative to that in the absence of these ligands and bivalent and trivalent cations, while the effects of K⁺and NO^-3 are insignificant. The effect of temperature in the range of 0-40 ℃ on the adsorption of U(Ⅵ) was investigated.