Abstract: In this article PE/EVA/CB systems were prepared by using melt-processing mixers and were extruded over a pair of elongated substantially parallel conductors spaced apart along the longitudinal length of the cable. In order to improve the properties of the conductive polymeric composites, antioxidants were adopted and the mechanisms were investigated. The results show that the antioxidants improve the stability of the PTC system, by improving the thermal stability of molecular structures of matrix polymers, especially in the case of containing 2% antioxidants.