Alzheimer's disease(AD)is a chronic neurodegenerative disease that severely affects the quality of life of the elderly.Its main pathological features include the deposition of β-amyloid protein to form senile plaques,neurofibrillary tangles caused by abnormal phosphorylation of tau pro-tein,as well as extensive neuronal loss and synaptic dysfunction.In recent years,mesenchymal stem cells(MSCs)and their exosomes(MSC-Exos)have attracted extensive attention due to their poten-tial in the treatment of neurodegenerative diseases.MSCs possess multidirectional differentiation po-tential,immunomodulatory capacity,and significant neuroprotective and repair effects.As an impor-tant signaling mediator of MSCs,MSC-Exos are a type of nanoscale double-layer membrane-structured vesicles secreted by MSCs,capable of carrying and delivering various bioactive substances.MSCs and their derived MSC-Exos have demonstrated good safety and efficacy in the treatment of AD.This arti-cle systematically reviewed the basic and translational research progress on MSCs and MSC-Exos in the treatment of AD in recent years.