Postoperative cognitive dysfunction (POCD) occurs mainly in aged patients. POCD may increase the mortality and morbidity. However, the mechanism of POCD is not clear yet and no effective therapy method was proved. According to our previous study, the central cholinergic system impaired by the anesthesia and surgery play a very important role in the POCD and donepezil an acetylcholinesterase inhibitor can prevent the POCD after isoflurane anesthesia in aged mice. Donepezil is a commercial medicine used for the Alzheimer Disease, which is tolerable and has minimal adverse events. In present study a multi-center randomized case control study was conducted and we hypothesized that donepezil attenuate the POCD.