The investigation results of the simultaneous effect of electric current and tensile deformation on the oxidation processes and electroconductive polyisoprene composition (EPIC) properties are presented in the study. The effects of the EPIC oxidation process under the conditions of complex factor action, consisting of the gaseous product emission and decrease of the oxidation rate at the final stage of the experiment, were disclosed. It was found out that the change in the electric resistance of EPIC aging with time was characterized by three sections: decrease, constant value area, and increase of the electric resistance. It was demonstrated that the values of the electric resistance and duration of the above sections depended on the deformation temperature and extent. (c) 2007 Wiley Periodicals, Inc.