Retrograde amnesia refers to the instantaneous memory and short-term memory aspects of memory loss is obvious, easy to forget, such as forgetting to turn off the lights, forgetting to turn off the gas valve, just said things and repeat, back and forth to say and so on. The patient’s long and distant memory is not affected, that is, the common people say that the near things can not remember, far things can not be forgotten. The common diseases of retrograde amnesia are Alzheimer’s disease and vascular dementia, both of which are mostly seen in elderly patients. Alzheimer’s disease is of unknown etiology and has a family genetic predisposition. In addition to forgetfulness, patients may also have personality changes and behavioral abnormalities, while vascular dementia occurs secondary to cerebral hemorrhage, cerebral infarction and other diseases. Memory loss often occurs six months after the onset of these two diseases, and patients often have weakness of the limbs, sensory disorders, slanting of the mouth and eyes, swallowing difficulties and other manifestations.