Objective:To investigate the incidence and related risk factors of cardiac surgery-associated acute kidney injury(CAS-AKI). Methods:A retrospective analysis of 1 575 patients undergoing cardiac surgery with cardiopulmonary bypass(CPB)between January 2009 and December 2011 in Nanjing First Hospital,was recruited. Univariate and multiple logistic regression models were employed for determining the association between the development of CSA-AKI and risk factors. Multiple Cox-proportional hazards modeling was used to evaluate the impact of CSA-AKI on the mortality of ICU and hospital length of stay. Results:Among this cohort,of 1 575 patients,534 (34%)occurred AKI. A total of 22 (1.4%)patients required renal replacement therapy. The overall in-hospital mortality rate was 1.3%(20 of 1575). Logistic regression analysis showed that mechanical ventilation duration (P < 0.001)CPB duration of ≥100 min(P < 0.01)erythrocytes transfusion (P < 0.001)and postoperative body temperature greater than 38℃ within 3 days (P < 0.05)were found to be independent risk factors of CSA-AKI,while ulinastatin use was associated with lower incidence for CSA-AKI (P < 0.05). CSA-AKI was significantly related to high in-hospital mortality (P < 0.05)especially in patients requiring RRT (P < 0.001). Conclusion:The incidence of CSA-AKI in patients form this cohort was 34%. Mechanical ventilation duration,erythrocytes transfusion and postoperative body temperature greater than 38°C within 3 days were independent risk factors of CSA-AKI. Ulinastatin was associated with lower incidence of CSA-AKI.