Astrocytes are the largest number of cells in the human brain，and their structures will change significantly in the early stage of ischemia. They express many neurotrophic factors and injury factors and are highly sensitive to ischemia，which can be used as an index to judge early ischemia. In recent years，great progress has been made in the study of the characteristics of astrocytes in cerebral ischemia. Astrocytes have dual effects on cerebral ischemia and can affect damaged brain tissues through various ways. However，the mechanism of action of astrocytes after cerebral ischemia is still unclear. How to control astrocytes to promote the recovery of neural function after brain injury has brought new directions and challenges to the treatment of cerebral ischemia and the development of new drugs.