Abstract: Ethylenediamine-grafted silica gel materials(EDA/SiO₂) for the adsorption of Zn²⁺ were prepared with the use of γ-chloropropyltrichlorosilane as coupling reagent and ethylenediamine as a surface-modifying reagent.The adsorption behavior of EDA/SiO₂ for Zn²⁺ and the effects of pH in Zn²⁺ solution,initial concentration,adsorption temperature and time were studied.The experimental results show that the pH value of Zn²⁺ solution affected the adsorption capacity of EDA/SiO₂ significantly,and the suitable pH range was pH 3.0~5.5 for the adsorption of Zn²⁺.The adsorption equilibrium data for Zn²⁺ could be fitted according to the Langmuir model.The results of the thermodynamic parameters of the adsorption of Zn²⁺ on EDA/SiO₂ show that this adsorption is an endothermic spontaneous process and increasing temperature is conducive to the adsorption.An interpretation was given for this,adsorption behavior of Zn²⁺ on EDA/SiO₂.Adsorption kinetic data could be fitted by the pseudo-second-order kinetic equation,and the fitting kinetic constants were related with the initial solution concentration.