Abstract: Amidoxime chelating fiber containing Fe(Ⅲ) was prepared from the reaction of partially amido-ximated PAN fiber with Fe³⁺.The studies of its adsorptive behavior for vat brown dye were performed in aqueous media.Results from the investigation on its adsorptive conditions,adsorption rules and adsorption kinetics show that the optimal adsorption parameters are pH:11.5～12.5,t=60 ℃(temperature) and time=60 min(time).Its adsorptive behavior for vat brown dye fits well with Langmuir and Freundlich isotherm equation.Furthermore,the relationship between adsorption time and sample concentration was investigated by employing various initial concentrations,from which the corresponding reaction order and rate constant were determined by differential method.Based on the Arrhenius equation,the activation energy(E_a) was calculated to be 11.55 kJ/mol from rate constants at different temperatures.The overall analysis demonstrates that the adsorptive behavior of the present amidoxime chelating fiber containing Fe(Ⅲ) for vat brown BR dye chara-cterizes first-order reaction with c=c₀e^-kt and k=32.01e^-E_a/RT.