@@ Usually, we refer to the disorder about consciousness, cognition, memory, orientation and sleep as mental disorders after surgery, it is a kind of reversible, fluctuant and acute mental disorders syndrome, namely POCD. Because of the degenerative changes in the nervous and the influence of injury to the nervous as anesthesia and surgery, the ratio of POCD is high to the elderly. With the development of modern anesthesiology, the open TCI is used in clinical intravenous anesthesia widely, it is more controllable , more simple and accurate than the traditional drug delivery methods. Because of individual differences, there is a big difference of drug effects on the standardized drug delivery method , it is difficult to the satisfaction of surgical stimulus intensity changing needs. Clinical practice shows that anesthesia effects can be simpler, more stable and secure if entropy index can serve as a variable feedback control and has a feedback regulation to the target-controlled rate , so closed loop target-controlled infusion appeared. Today ,we will study the POCD of elderly under entropy index and intravenous anesthesia.