Abstract: A kind of α-ketoglutaric acid modified chitosan (KMCS) was synthesized with the reaction of α-ketoglutaric acid and chitosan to obtain Schiff base and with the reduction reaction by NaBH₄. The structure of KMCS was characterized by FT-IR, XRD and SEM. The effects of initial pH, adsorption time, temperature and other factors on U(Ⅵ) adsorption on KMCS were investigated. The experimental results show that under the condition of 35 ℃, pH=4.0, adsorption time of 45 min, and U(Ⅵ) initial concentration of 5 mg/L, the percentage removal of U(Ⅵ) adsorbed by KMCS is higher than 99%, which leads to the U(Ⅵ) concentration in the rest solution lower than the national emission standard (0.05 mg/L). The KMCS can be regenerated with the solution of 8% NaOH, and there is no obvious decline after regeneration. The SEM images of the samples show that the KMCS has a rough surface and an uneven porous structure. FT-IR analysis demonstrates that—COOH groups of KMCS are the main binding sites of U(Ⅵ).