Mild cognitive impairment refers to a degenerative disease of the central nervous system，with a progressive decline of memory or other cognitive functions as the main clinical manifestations.It is a transitional stage between normal cognition and dementia.In traditional Chinese medicine，mild cognitive impairment is classified as amnesia，forgetfulness，dementia，and other diseases.The location of the disease is mainly in the heart and brain，and the pathogenesis is closely related to the disharmony between Ying and Wei circulation.There are multiple relationships between the essence of Ying-Wei and neurovascular units.According to the functional similarity among Ying Qi，neurons，and astrocytes，and the correlation among Wei Qi，blood brain barrier，and microglia cells，it is pointed out that the disharmony between Ying and Wei circulation is important pathogenesis of mild cognitive impairment，including “weak Ying and strong Wei” and “weak Wei and Ying stagnation”，which results in neurovascular unit dysfunction and structural changes，brain decline，and cognitive impairment.Therefore，it is necessary to expand the application of Ying-Wei theory in encephalopathy and strengthen the exploration of Ying-Wei theory in mental diseases，so as to provide new ideas for the prevention and treatment of mild cognitive impairment with traditional Chinese medicine.