Cortistatin, cloned from cerebral cortex in mammal in 1996, is a sort of polypeptide with multiple biological activities and shares high structural homology with somatostatin. It is widely distributed in tissues and organs of human body, such as brain, coronary artery, stomach, kidney, testis, leukocyte and immunological system. A growing evidence indicates that cortistatin exerts many kinds of biological effects including modulating the process of study and memory, inducing sleep, inhibiting inflammation and regulating endocrine metabolism and homeostasis of cardiovascular system. And these effects are mediated by binding somatostatin receptors, grow hormone secretagogues receptor-1a and Mas-related gene X2 receptor. Cortistatin is considered an important factor regulating the balance of body homeostasis.