Memory is a complex and dynamic process, and the understanding of the basic mechanisms of learning and memory has benefited from the study of the simple nervous system of a lower invertebrate, the sea hare (aplysia). Memory is the ability to process, store, and recall messages and is associated with learning and perception. The process of memory involves the processes of sensory input → sensory memory → short-term memory → long-term memory → recall of stored messages. Short-term memory involves the balance between phosphorylation and dephosphorylation of specific proteins, while long-term memory involves the synthesis of new proteins in addition to changes in phosphorylation of specific proteins. Damage to different parts of the cerebral cortex can cause different types of memory impairment, such as damage to the hippocampus in the temporal lobe, which mainly causes spatial memory impairment, and damage to the blueprint and amygdala areas, which mainly causes emotional memory impairment. Memory impairment is one of the most frequently impaired cognitive functions after brain injury, which refers to the inability to rerecognize or recall the material that is recognized or manifested as incorrect rerecognition or recall. It mainly includes the following forms of memory: 1. Transient memory: it refers to the memory that can still keep the instantaneous image in the mind when the sensory stimulation stops, and it is the first stage of the memory system, and the retention time is counted in milliseconds, and the longest time is 1-2 seconds. Instantaneous memory disorder is related to the damage of cortico-cortical circuit. 2, short-term memory: refers to the information maintained within 1 minute of memory, is the instantaneous memory and long-term memory of the intermediate stage. The average person’s short-term memory capacity (memory breadth) is 7±2 memory units. Short-term memory impairment is related to prefrontal cortex damage. 3.Long-temporal memory: It refers to the memory in which the information is retained in the mind for more than 1 minute, even for a lifetime, and is the third stage of the memory system. The source of its information is the processed content of the short-term memory stage, which is usually stored after retelling. The information of long term memory is in a latent state when not in use and is extracted into short term memory when needed. Long-term memory impairment is associated with damage to the hippocampus and surrounding structures. Memory impairment can be assessed functionally by memory scales or cognitive scales, such as Wechsler Memory Scale, MMSE, etc. Memory disorder training: 1, reading aloud method: repeated recitation of the information that needs to be remembered, in the recitation of the subsequent , the brain recalls the pictorial impression consistent with the recitation. 2. Cueing method: use the first letter or the first word of the active information to remind the memory. 3. Narrative method: the information to be remembered is integrated into a story, and when the patient expresses the storyline, the memorized information is continuously narrated, prompting the patient to engage in the arranged work. 4. Impression method: produce an image in the patient’s brain to help memorize. 5.Establishing a routine program of daily living activities: e.g. the same meal times. 6.Assistive method: Let the patient utilize journaling to fill out forms to record the schedule of activities. Drugs to improve memory: cytarabine, strychnine A tablets, and ampicillin, etc.