Abstract: Thorium, as an important natural radioactive element, is receiving an ever-increasing interest as nuclear fuel alternatives to uranium in nuclear power industry. In view of the extensive application, the development of reliable methods for the monitoring, and the recovery of Th from environmental and geological samples are of particular significance. Herein, a novel sorbent of Th(Ⅳ), phosphonate-functionalized mesoporous silica (NP10), was synthesized, and the adsorption of Th(Ⅳ) from aqueous solution using NP10 was studied in batch processes under varying operation conditions of pH, temperature, adsorption time and Th(Ⅳ) concentration. The experimental results show that the adsorption of Th(Ⅳ) by NP10 is ultra-fast, and the sorption process reaches equilibrium after about 30 min. The adsorption process can be well described by the Langmuir equation and the maximum sorption capacity is estimated to 149 mg/g at temperature of (14±1) ℃. When the adsorption temperature is up to 40 ℃, the maximum sorption capacity reaches 192 mg/g. It is also found that the adsorption percentage of Th(Ⅳ) by NP10 increases rapidly with pH from 0.9 to 4, whereas ionic strength shows no obvious effect on the adsorption. Moreover, the adsorption percentage of Th(Ⅳ) by NP10 increases with the mass of NP10 until almost complete adsorption (>97%).