The adsorption of uranium in the presence of different cations namely Cd2+, Zn2+, La3+, Y3+, Sc3+ on activated charcoal from aqueous solution was studied at room temperature 23 +/- 0.2-degrees-C. Their effect on uranium adsorption has been correlated with the ionic potential, z/r of cations. It was observed that die cations with larger (z/r) reduced the uranium adsorption more than the cation with smallest (z/r) value. The Langmuir and Dubinin-Radushkevich (D-R) isotherm equations have been applied to the data and the values of parameters of these isotherm equations were evaluated. The mean energy of adsorption, E was also calculated from the adsorption energy constant, K' values determined from D-R isotherm equation. Wavelength dispersive X-ray fluorescence spectrometer was used for measuring uranium concentration in solutions.