The article reviews the emerging roles of astrocytes in neural circuit development, highlighting their critical functions in synapse formation, maturation, and elimination. Astrocytes, initially thought to be passive support cells, are now recognized as key regulators of synaptic development and function. They control the formation of both excitatory and inhibitory synapses through secreted and contact-mediated signals. Astrocyte-secreted molecules, such as thrombospondins (TSPs), hevin, SPARC, and glypicans, play crucial roles in promoting synapse formation and maturation. Astrocyte contact with neurons also influences synapse development, enhancing presynaptic activity and postsynaptic receptor expression. Additionally, astrocytes contribute to synapse pruning by inducing the expression of complement proteins, which are then cleared by microglia. The article discusses the implications of these findings for understanding and treating neurodevelopmental and psychiatric disorders, such as autism, schizophrenia, and Rett syndrome, where astrocyte dysfunction is implicated. Future research will focus on elucidating the molecular mechanisms underlying astrocyte functions and their potential therapeutic applications.The article reviews the emerging roles of astrocytes in neural circuit development, highlighting their critical functions in synapse formation, maturation, and elimination. Astrocytes, initially thought to be passive support cells, are now recognized as key regulators of synaptic development and function. They control the formation of both excitatory and inhibitory synapses through secreted and contact-mediated signals. Astrocyte-secreted molecules, such as thrombospondins (TSPs), hevin, SPARC, and glypicans, play crucial roles in promoting synapse formation and maturation. Astrocyte contact with neurons also influences synapse development, enhancing presynaptic activity and postsynaptic receptor expression. Additionally, astrocytes contribute to synapse pruning by inducing the expression of complement proteins, which are then cleared by microglia. The article discusses the implications of these findings for understanding and treating neurodevelopmental and psychiatric disorders, such as autism, schizophrenia, and Rett syndrome, where astrocyte dysfunction is implicated. Future research will focus on elucidating the molecular mechanisms underlying astrocyte functions and their potential therapeutic applications.