With wide applications of electromagnetic instruments and equipments in medical treatment, scientific research and national defense, and daily life items of computers, mobile telephones, and microwave ovens etc, electromagnetic radiations have brought us great benefit. However, there are potential damages with electromagnetic radiations,e.g. the electromagnetic pulse (EMP), which is not ionizing radiation but can cause vibration of atoms or molecules and alter electron energy levels. It has been reported that EMP could decrease the learning and recollection ability of mice and rats through inducing metabolic disorder of neurotransmitter in mice brain and affect the brain wave of anesthetized rats. EMP also has some effect on immune, procreation and endocrine system of mice.