[en] Some random three-component copolymers have been prepared by condensing of formaldehyde with various aromatic amines. The compositions of the copolymers have been determined by known methods. selective complexation of copolymers have been carried out with PAA, PEI, PVP and some transition metal ions (e.g., Cu²⁺ )by adding the components in various sequences. The relative complexation ability of different -NH₂ groups, associated with the various comonomer units, has been interpreted in terms of the these complexes has been studied by conductometry. potentiometry and viscometry techniques. A scheme has presented to explain the mode of interaction of the various components