Abstract: Objective:To investigate the changes of coagulation function in patients undergoing aortic replacement surgery in plateau area,and to evaluate the feasibility of prothrombin complex(PCC) combined with fibrinogen(FIB) treatment.Method:A total of 93 patients who underwent aortic replacement surgery in cardiac surgery department of Qinghai cardiovascular and cerebrovascular disease hospital in March 2016-February 2018 were selected as the subjects.There were 42 cases of control group(group A) and 51 cases(group B) with prothrombin combined with fibrinogen.The two groups were detected at admission,stop cardiopulmonary bypass and protamine and heparin after 5 minutes and 2 hours in the thrombin time(TT),prothrombin time(PT),activated partial thromboplastin time(APTT),fibrinogen(FIB),platelet(PLT) count,the number of first day postoperative hemorrhage the amount of red blood cell transfusion and postoperative.Result:There was no significant difference in TT,PT,APTT,FIB and PLT between the two groups at admission and in cardiopulmonary bypass and after 5 minutes of protamine and heparin(P>0.05).There were significant differences in TT,PT,APTT,FIB and PLT(P<0.05) in the two groups after 2 hours of operation.There was a statistically significant difference in the amount of bleeding from the two groups after first days and the amount of red blood cells after operation(P<0.05).In group A,3 cases died after operation,and 2 cases died after operation in group B.All the other patients were cured and discharged.Conclusion:In plateau area,coagulation dysfunction is more common in perioperative period.During perioperative period of aortic replacement,PCC combined with FIB can significantly reduce postoperative bleeding risk,and the treatment effect is remarkable.