Straw-supported ion imprinted polymer sorbent was prepared by surface imprinting technique combined with activators generated by electron transfer for atom transfer radical polymerization (AGET ATRP). The ability of the imprinted sorbent to adsorb La3+ ions was assessed by batch adsorption technique. The crosslinking density of the ion imprinted polymer (IIP) on the surface of straw exerted great influence on the sorption property. The IIP with appropriate crosslinking density displayed the highest sorption capacity, fastest sorption rate and best selective sorption ability. The maximum sorption amount was 125 mg/g, and the sorption equilibrium could be reached within several minutes. The adsorption mechanism studied by X-ray photoelectron spectroscopy (XPS) revealed that the sorption of La3+ ions was realized mainly through interactions with the C-N, C-O and C=O groups. The imprinted sorbent could be repeatedly used for ten times without any significant loss in the initial binding affinity. (C) 2016 Elsevier B.V. All rights reserved.