Ras-related C3 botulinum toxin substrate 1 (Rac1) is a member of the small Rho guanosine triphosphatase (GTPase) family, having GTPase activity and serving as a " molecular switch" in a variety of cell signal transduction processes.It is involved in cell migration, adhesion, proliferation and apoptosis.Rac1 can affect the migration of neural crest cells through regulating the actin polymerization of neural crest cells and the formation of membrane protrusions, possibly leading to disorders related to abnormal neural crest migration, such as congenital megacolon and cardiac outflow tract defects.In this article, the main biological functions of Rac1 and its role in the mechanism of ente-ric neural crest cell development were described.