Abstract: As a traditional Chinese medicine, Astragalus membranaceus has been widely used over 2,000 years in China. The primary active component of Astragalus membranaceus is astragaloside Ⅳ which has extensive pharmacological activities, especially on the treatment of cerebral ischemia/reperfusion injury. According to vast information from literatures regarding astragaloside Ⅳ published in recent years at home and abroad, we summarize cerebral protective effect of astragaloside Ⅳ and its underling mechanism, in hopes of offering more clues for further research as well as clinical application of AS-Ⅳ.