Objective: The aim of this study was to define the incidence and risk factors of AKI in adult patients, who underwent open heart surgery with cardiopulmonary bypass (CPB). Subject and method: the authors carried out a retrospective, comparative case-control study. From January 01/2013 to October 30/2014 data of 181 adult patients, who underwent cardiac surgery with CPB at No.108 Military Central Hospital were retrospectively reviewed. The AKI was defined by criteria of the Acute Kidney Injury Network (AKIN). Patients preoperative, intra-operative, and CPB characteristics, as well as postoperative management variables were eva-luated for association with AKI using logistic regression analysis. Result: Of all 181 cardiac surgery patients, 31 presented with AKI postoperatively (17.1 percent), of these 19.3 percent needed hemodialysis (accounted for 3.3 percent of all patients). The risk factors that were independently associated with AKI were: age 70 years old, COPD, previous stroke, NYHA class III or IV, EF 40 percent, preoperative serum creatinine concentration 110 umol/l, prolonged CPB time ( 120min) and cross-clamp time 60min, intra-operative: vasoconstrictors, re--exploration for bleeding, and ventilation time after surgery 48h. Conclusion: Risk factors of acute kidney injury in adult patients after cardiac surgery as followed: age 70 years old, congestive heart failure, COPD, previous stroke, preoperative serum creatinine concentration 110 umol/l, CPB time 120min, cross-clamp time 60min, intra-operative vasoconstrictors, re-exploration for bleeding, severe hemodynamic complications, sepsis and prolonged ventilation after surgery.