The effects of electric field ( E ) on tissue are the main subject of many investigations. Importance of this subject comes from the electrical properties of the cell membrane and its sensitivity to the changes in electrical conditions. Permeabilities of membranes to various ions can change by the effect of electric field depending on the conductivity of them. Performances. of cells and tissues change due to the differences between membranes permeabilities to various ions and molecules. The aim of this study. is to determine lipid peroxidation and SOD levels in spleen and testis tissues exposed to different intensities and directions of electric fields.