AbstractResults are reported obtained by the ESR study of the mobility of spin labels bonded at the side‐chain ends of copolymers of the polymethacrylamide type. The correlation times, γ, characterizing the mobility of the spin label were determined by analyzing the EPR spectra of 1% methanolic solutions of copolymers. The log γ vs 1/Tdependences within the temperature interval 233‐313 K studied are linear and are characterized by the same activation energy,Ea= 3 kcal/mole (12.5 kJ/mole), for both types of the side chains. The mobility of the spin label bonded at the end of the side chain of the oligoglycine type is lower than that of the spin label bonded at the end of the equally long side chain of the methylene