The influence of 0-10% concentration of PP contained in PE on electric deterioration stability is investigated. It is shovn, that introduction of small concentration of PP into PE (1−2 weights %) increases stability versus eroision and oxidation cansed by electric charge action and leads to electric durability of PE. There is a hypothesis advanced, that for all mixtures of polymers in two – and three component systems, compatibile and uneompatibile, there is some fraction of medifier (for one of polymers up to 10%), at which, sharp, avalanche – like changing of structure and electrophysical properties will take place. These changes can be directed both improvement, and to deterioration of properties of initial parameters of polymers of composition.