Mechanochemical processes in commercial and model SBR rubbers containing different stabilizers were investigated. The influence of chemical structure and concentration of stabilizers in the temperature range from 20-170 degrees C and in the presence of air, i.e., under conditions similar to that in industrial processes, were studied. Stabilizers used were diaryl-p-phenylene-diamine, alkyl-aryl-p-phenylene diamine, polynuclear phenol, aryl-alkyl phenol, and alkyl-alkyl phenol. It was found that mechanochemical processes in SBR rubbers are less developed in the temperature region from 70-130 degrees C, so the influence of stabilizer is less expressive. During increasing temperature (130-170 degrees C) structure and concentration of stabilizers both show a strong influence on type and intensity of mechanochemical processes in SBR rubbers: p-phenylene-diamines favor processes of linear degradation, while phenol stabilizers direct them toward branching and crosslinking, which is more expressed in the presence of aryl-substituted phenols than alkyl-substituted phenols. This fact is based on the differences in stability of free stable radicals of p-phenylene-diamines, alkyl-substituted phenols and aryl-substituted phenols. The fact that phenol stabilizers are involved in chain degradation as well as in branching and crosslinking processes during rubber processing, can be of high practical importance;