Abstract: [Abstract]〓Objective〖WTBZ〗〓To explore the risk factor of cognitive function after coronary artery bypass grafting（CABG）.〖WTHZ〗Methods〖WTBZ〗〓According to the inclusive criteria setted before the research，we gathered relevant data of preoperation，postoperation，and recovery condition after operation of 80 patients with CABG in our hospital from March 2012 to March 2013 before operation.Delirium one day before operation and the first to the third day after operation were assessed with CAMICU.Cognitive function one day before operation and the seventh day after operation were assessed with MMSE.〖WTHZ〗Results〖WTBZ〗〓There were 17 patients（21.25%）developed postoperative delirium during 3 days after operation.Univariate analysis showed that age，stroke history，time to stop jumping，visual analogue score（VAS），hypocardia syndrome and preoperative MMSE were risk factors for postoperative delirium.Multivariate Logistic regression analysis showed that older than 65 years old，stroke history，too long time of cardiac arrest，higher postoperative VAS score，low cardiac output syndrome and lower preoperative MMSE score were independent risk factors in patients undergoing CABG surgery developed delirium.On the seventh day after operation，there were 25 patients（31.25%）developed cognitive dysfunction.Univariate analysis showed that age，history of hypertension，history of diabetes，duration of arrest，intraoperative oxygen saturation，postoperative VAS score，hypocardia syndrome and preoperative MMSE were risk factors for postoperative cognitive dysfunction.Multivariate Logistic regression analysis showed that older than 65 years old，too long time for cardiac arrest，diabetes，higher postoperative VAS score，low cardiac output syndrome and lower preoperative MMSE score were independent risk factors for patients undergoing CABG developed cognitive disorders.〖WTHZ〗Conclusion〖WTBZ〗〓Older than 65 years old，history 〖JP+1〗of stroke，too long time of cardiac arrest，diabetes，higher〖JP〗〖LM〗postoperative VAS score，low cardiac output syndrome and lower preoperative MMSE score were risk factors for patients with CABG developed delirium and cognitive impairment.