Abstract: Ni-Fe(Ⅱ) Prussian blue/carbon nanotube sponge, which has both adsorption and ion-exchange properties, was synthesized by combining the template and in-situ growth method. Then stable isotope of Cs was used to simulate radionuclide to study the adsorption effect of the composites. The results show that the sample has a three dimensional porous structure as same as polyurethane foam. Moreover, the carbon nanotubes on the surface of sponge are successfully modified with Ni-Fe(Ⅱ) Prussian blue. It shows that the ternary spongiform matrix contains 1.38% Ni-Fe(Ⅱ) Prussian blue. Both ICP and M-ssbauer spectrum analyses indicate that K⁺ in Ni-Fe(Ⅱ) Prussian blue is exchanged by Cs⁺, and the absorption capacity is 698 μg/g.