The radically initiated copolymerization of three-component system with participation of bifunctional monomer – N-allylmaleimide, trans-stilbene and maleic anhydride has been carried out. The discrepancy of real compositions of triple copolymers with free-monomer chain growth calculated on model has been established. This fact has been interpreted from position of formation of intermolecular p–p-complexes participating in elementary chain growth reactions. It is shown that the macromolecules of the synthesized triple copolymers consist of dyad complexomers at their various content in macrochain.