An aminated bagasse (AB) with high-adsorption capacity for mercury ions was prepared by grafting copolymerization of acrylonitrile onto sugarcane bagasse, followed by aminating with chelating molecule diethylenetriamine. Effects of grafting conditions such as irradiation dosage, acrylonitrile concentration, and solvents on the grafting yield were investigated. The adsorption performance for mercury ions were evaluated by batch adsorption experiments and kinetic experiments. The results show that AB is effective for the removal of mercury over a wide range of pH > 5. Adsorption isotherms of mercury ions on the modified bagasse can be well described by Langmuir equation. The equilibrium adsorption amount could be as high as 917.4 mg/g, and the removal percent of mercury ions can achieve 99%. The kinetic adsorption results indicate that AB could remove 80% of mercury ions in 2 h and 24 more hours are needed to achieve adsorption equilibrium. Regeneration experiments show that the adsorption capacity of recycled AB still can reach the level of 96% after four cycles. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 2854-2861, 2010