Melatonin is a hormone secreted by the pineal gland, and its chemical structure was 5-meth-oxy-N-acetyl tryptamine, the physiological function of inhibiting gonad, thyroid, adrenal gland, parathyroid gland and pituitary function, inhibit precocious puberty, reduce pituitary Melanotropin secretion; and has a central nervous system function, can improve the convulsion the threshold, cause drowsiness. When pinealectomy after the animal experiment showed hyperplasia of the glands, weight increase, especially sex and se-xual organs of immature rats early, pituitary secretion of LH and FSH increased, increasing secretion of thyroid and adrenal cortex hormone melatonin. More reduced pituitary MSH and whiten the skin of this role. Effects on the central nervous system, in the human EEG showed slow rhythm, increased seizure threshold, sleepiness, but does not affect their behavior and personality, of temporal lobe epilepsy and Ba Jinsen disease can reduce the motor nerve Abnormal EEG changes.