Objective To explore the independent risk factors of the prolonged time of retention ICU after type A aortic dissection operation,to establish a corresponding perioperative risk assessment system.Methods A total of 509 consecutive patients with type A aortic dissection were enrolled in the study from September 2011 to May 2016,among which,418 patients received emergency operation.The prolonged retention time of ICU was considered as endpoint event.A perioperative assessment system was established through the analysis of related risk factors of the most common complications after type A aortic dissection operation.The possible risk factors of prolonged retention time of ICU were introduced into a single factor analysis.The meaningful variables in the single factor analysis were introduced into logistic regression analysis.The independent risk factors which were obtained from logistic regression analysis were used to establish risk prediction modeL,and the ROC curve and Hosmer-Lemeshow goodness of fit test were used to evaluate the model.Results The perioperative mortality rate was 8.64％,the prolonged retention time of ICU was 5.06 days,and 98 cases exceeded 7 days.The results of logistic regression analysis showed that age,the history of stroke,obesity,emergency operation,cardiopulmonary bypass time,deep hypothermic circulatory arrest time,renal inadequacy,massive transfusion,hypoxemia,and pulmonary infection were the independent risk factors for prolonged retention time of ICU.Accordingly,a mathematical model was established.The area under ROC cure for prediction model(AUC) =0.761,Hosmer-Lemeshow goodness of fit test P =0.512.Conclusion The logistic model estabhshed in this study can successfully predict ICU retention time after type A aortic dissection operation,and the efficacy was predicted satisfactorily.