Objectives To investigate the risk factors in patients with(Kidney Disease:Improving Global Outcomes)KDIGO stage 1 acute kidney injury(AKI)underwent heart valve surgery,in order to provide evidence for the early prevention and treatment of stage 1 AKI after heart valve surgery.Methods Clinical data of patients underwent heart valve surgery from January 2016 to April 2017 in The First Affiliated Hospital of Sun Yat-Sen University were collected retrospectively.According to the 2012 KDIGO guideline to definite AKI,patients were divided into non-AKI group and stage 1 AKI group.Prognosis of patients with stage 1 AKI was analyzed,and meanwhile risk factors were further analyzed.Results A total of 560 patients were enrolled,including 395 patients in non-AKI group and 165 patients in stage 1 AKI group.Stage 1 AKI accounted for 86.39%of AKI.In non-AKI group and stage 1 AKI group,renal replacement therapy during hospitalization(2.78%vs.16.97%,P=0.002),mechanical ventilation use duration[12(8-21)h vs.22(17-50)h,P<0.001],intensive care unite(ICU)stay duration[1(1-2)d vs.2(2-5)d,P<0.001]and in-hospital death(2.53%vs.10.91%,P<0.001)were significantly different.Age(OR=1.412),body mass index(BMI)(OR=1.107),previous cardiac surgery(OR=4.033),preoperative albumin(OR=0.929),left ventricular end-diastolic diameter(OR=1.027)and cardiopulmonary bypass duration(OR=1.008)were independent risk factors for early stage 1 AKI.Conclusions KDIGO stage 1 AKI is the main stage of AKI in the early stage after cardiac valve surgery,accounting for more than 80%.The risk factors for early KDIGO stage 1 AKI after heart valve surgery were age,BMI,previous cardiac surgery,left ventricular end-diastolic diameter and cardiopulmonary bypass duration.Positive prevention and treatment should be carried out according to the risk factors.