The purpose of this article is the study of effects of high voltage AC stray current (220 and 380 VAC) on the durability of concrete. In rainy condition, high voltage AC current can leakage into water saturated concrete power pole by creeping AC current through their insulators. In Iran, large budgets are annually spent for replacing degraded concrete power poles with new ones. There is not any research on the above mentioned subject and the history of this research is related to the authors of this paper. Therefore, this study is a new work in the field of concrete. In this study, the degradation effects and mechanisms of the AC stray current on water saturated concrete were investigated via laboratory tests. They included electrical and electrochemical tests. Based on the results of the tests, AC stray currents can reduce the durability of water saturated concrete by non-distribution current, thermal and shrinkage stress mechanisms. Application of silica fume and reducing w/c ratio increases the resistance of concrete against destructive effects of the AC stray current and increases its durability.