The sorption of Cu, Zn,Ni, and Co in unit metal and binary Cu-Zn or Ni-Co systems was examined in 0.05 mol/L KClO₄ solution as a function of pH. At higher pH values, copper sorption was not affected by Zn but slightly decreased at lower pH. Zn sorption decreased in the presence of Cu, especialy when a high initial concentrations of metal were used. Co and Ni coexistence caused increases of pK_Co(int) and pK_Ni (int) and with a higher initial concentration pK_Co(int) incresed to a greater extent.