Amidoxime fiber synthesized with a commercial PAN fiber was packed in 2 cm-diameter spherical shells made of plastic net. The adsorbent balls were then packed in a cage through which seawater passed. This shape of adsorbent increased the contact efficiency between adsorbent and seawater but might decrease the desorption rate of uranium adsorbed in the balls. The rate of desorption from 2 cm-diameter adsorbent balls packed in a column was nearly equal to the value obtained with completely dispersed amidoxime fiber. however, when the eluent velocity through the balls was higher than 2-4 cm.s-1 and the void fraction in the balls was higher than 0.8. Most of the liquid held in the balls was removed with a light centrifugation.