The interaction between sodium dodecyl sulfate (SDS) and polyacrylamide (PAM) has been studied by electron spin resonance (ESR) and UV methods using 2,4-dinitrophenylhydrazone of 2,2,6,6-tetramethyl-4-piperidin-1-oxyl (DNPHTEMPO) as a probe. Our results confirm that micellization on the polymer chains occurs at a lower surfactant concentration (critical aggregation concentration (CAC)) than the critical micelle concentration (cmc) of SDS and that a large number of free surfactants are in equilibrium with bound surfactants in this micellization regime. Polymer-complexed micelles are formed by complexation of SDS micelles with PAM. Binding of the spin probe to the surfactant aggregates is revealed by a substantial increase of the apparent rotational correlation time (tau (C)) and a decrease of the nitrogen hyperfine splitting constant (AN) relative to the corresponding parameters for the free radical in bulk water. The micropolarity of the solution decreases with increasing SDS concentration. The polymer-micelle aggregates form a more compact structure at the binding sites, The two breakpoints of the SDS-PAM system, CAC and the polymer saturation point (PSP), were obtained from the maximum absorption bands lambda (max).