Acute Kidney Injury(AKI) is of the serious complications in patients with undergoing on-pump cardiac surgery. End stage kidney failure requiring dialysis therapy after cardiac surgery is associated with more than 60% mortality rate. Involvement of AKI after on-pump cardiac surgery increases the mortality rate 19 times. suPAR is one of the novel biomarker which has potential prognostic value for renal dysfunction in patients with undergoing on-pump cardiac surgery. Early diagnosis and prompt intervention to prevent AKI has great importance for management of postoperative cardiac patients.