Abstract: The activated sludge got from sewage treatment plant was cultivated by sodium acetate. Extracellular polymeric substances(EPS) were extracted through NaOH extraction method. The adsorption behavior of EPS on uranyl was studied by static method. The influences of temperature, pH, adsorption time, the dosage of the EPS and ionic strength on the effect of adsorption of uranyl were discussed. Thermodynamic and kinetic of adsorption were discussed, too. The infrared spectra of EPS before and after adsorbing uranyl were compared. The experimental results indicate that the best adsorption temperature is 25 ℃, the best adsorption time is 120 min, and the best dosage of EPS is 300 mg/L. The ionic concentration has a strongly impact on adsorption. The study of adsorption thermodynamics indicates that the adsorption process conforms to the Freundlich adsorption model. The study of adsorption kinetics indicates that the adsorption process conforms to second order reaction kinetics model.