The study aimed to investigate the treatment effect of marjoram leaves on brain tissue and some biochemical properties that exposed to magnetic field (MF). Magnetic fields may cause heating of the skin and the tissue, which could lead to several disorders as increase the production of reactive oxygen species. Animals have the effective enzymatic antioxidant defense system including catalase (CAT), superoxide dismutase (SOD), and Glutathione (GSH) and Glutathione reductase (GSH-Px) enzymes. Lipid peroxidation in blood (erythrocytes) was measured as the amount of malon dialdehyde (MDA). This system allow for scavenging of reactive oxygen species ROS and leading to protection of cells from oxidative damage. Fruits, plants and vegetables contain high amounts of antioxidants, like polyphenols, vitamin C, vitamin E, β-carotene, and lycopene. Plants as Marjoram contains several acids as urosolic acid, carnostic acid, and carnosol which used as free radical scavengers. So it protect organs as liver , brain and kidney and enhance the antioxidant activities .