Amidoxime modified Trametes trogii pellets were prepared by sequential reaction of fungal surfaces with glutaraldehyde, diaminomaleonitrile and hydroxylamine. Maximum biosorption capacities of the modified and native pellets were found to be 447.4 and 238.2 mg U(VI) g(-1) fungal pellets, respectively. Biosorption equilibriums were established in about 45 min and the correlation regression coefficients show that the adsorption process can be well-defined by Langmuir equation. The biosorption of U(VI) ions was well described by the pseudo-second order kinetic model. The variations in enthalpy and entropy for the biosorbents were also calculated.