Abstract: Objective To investigate preoperative renal function and realative influencing factors in Stanford type B aortic dissection. Methods From January 2004 to September 2013,151 consecutive patients with Stanford type B aortic dissection were admitted to hospital.95 age and sex mached healthy people were taken as the control group.The fasting venous blood was collected to test the renal function.The primary entry tear and extent of aortic dissection was measured by CTA.The aortic valve insufficiency and left ventricular size were measured byColor Doppler ultrasonic diagnostic apparatus.Various factors that may affect renal function were analized by Pearson correlation analysis. Results The level of renal function indexes(BUN,CERA) existed difference between aortic dissection group and control group(t=-2.903,-3.110;P=0.004,0.002).Among three subgroups,UA existed difference between acute stage group and subacute stage group(F=3.776;P=0.025).Trough correlation analysis,BUN negatively correlated with left ventricular end-diastolic diameter and end-systolic diameter,CERA negatively correlated with patients gender and patients age,positively with the left ventricular end-diastolic diameter and end-systolic diameter and conditions of the left renal artery opening.UA negatively correlated with patients gender and patients age,positively with left ventricular end-diastolic diameter and end-systolic diameter and extent of aortic dissection and conditions of the left renal artery opening. Conclusion There exists damaged renal function in preoperative Stanford type B aortic dissection.The gender and age,left ventricular diameter,extent of aortic dissection and left renal artery opening condition have certain effects on the preoperative renal function of Stanford type B aortic dissection.