The adsorption properties of U(VI) with a new type of fibrous and polymeric adsorbent containing amidoxime chelating functional group (FPAO) from seawater was studied by the method of the static state adsorption at 25degreesC. The optimum conditions of the adsorption were determined by investigating the influence of the concentrations of FPAO, U(VI), feed acidity, temperature, and the shape and size of FPAO on the adsorption equilibrium. The maximum adsorption capacity of U(VI) in theory was deduced to be 384.6 mg/g dry FPAO by Langmuir isothermic adsorption equation. Freundlich isothermic adsorption equation, expressed as Q=4.116 [U(VI)](0.4293), shows that this process can taken place easily because the adsorption factor 1/n equals to 0.4293, which is in the region of 0.1-0.5. Meanwhile, the adsorption kinetics of U(VI) with FPAO was also studied. The rate equation of the adsorption reaction was determined as -d[U(VI)]/dt=k[U(V)IFPAO](1.70)/[H+] and the rate constant of the adsorption reaction k was calculated to be 0.5912 min(-1) for pH 6.0 and ionic strength 0.1 mol/l. The activation energy of the adsorption reaction was calculated to be 28.54 kJ/mol. On the basis of the kinetics results, the adsorption mechanism of FPAO on U(VI) was discussed. The diffusion of uranium ion in internal of the adsorbent was thought to be the rate-controlling step.