Due to its high adsorption capacity and adsorption efficiency, polymer gel shows excellent performances in the treatment of wastewater containing thorium. In this work, glutaraldehyde cross-linked N-(4-Aminobenzoyl)-ʟ-glutamic acid modified chitosan (CCS-AGA) was used to adsorb Th(IV) ions from aqueous solutions for the first time. FT-IR and SEM results revealed the chemical structure and surface morphology of this material. The influence of solution pH, contact time and initial concentration of Th ions on the adsorption of Th(IV) by CCS-AGA was investigated. The experimental data suggest that the adsorption behavior of CCS-AGA could be accurately predicted by the Langmuir model. The maximum theoretical adsorption capacity of CCS-AGA for Th(IV) was 162 mg/g. Moreover, this material exhibited excellent reusability and adsorption selectivity for Th(IV).