Objective To investigate the significance of urine neutrophil gelatinase associated lipocalin (NGAL ) and renal injury molecule-1 (KIM-1) in predicting the acute kidney injury (AKI) in children with congenital heart disease after operation .Methods From April 2014 to December 2015 ,67 cases of cardiopulmonary bypass in children with congenital heart disease were studied in our hospital ,all patients were divided into AKI group (n=24) and non AKI group (n=43) by pRIFLE standard .Serum creatinine , urine NGAL and urine KIM-1 levels were compared between the two groups before and after the operation ,the receiver operating characteristic curve (ROC curve) and the area under the curve (AUC) were used to evaluate the value of NGAL and KIM-1 in pre-dicting the postoperative AKI in children with congenital heart disease .Results There was no significant difference between the two groups in preoperative and postoperative 2 h and 4 h creatinine (P>0 .05) ,but the levels of postoperative 12 ,24 ,48 h creati-nine in the non AKI group were significantly lower than those in the AKI group (P<0 .05) .The NGAL level of postoperative 2 ,4 , 6 ,12 h in non AKI group was significantly lower than that in AKI group (P<0 .05) ,but there was no significant difference in the level of postoperative 24 h urine NGAL between the two groups (P>0 .05) .There was no significant difference between the two groups of patients with postoperative 2 h urinary KIM-1 (P>0 .05) ,postoperative 4 ,6 ,12 ,24 h urinary KIM-1 levels in the non AKI group were significantly lower than those in the AKI group (P<0 .05) .The optimal time point separate detection of urinary NGAL levels to assist in diagnosis of AKI after 12 h ,AUC was 0 .834 (95% CI:0 .631-0 .912);the best time point separately to detect the level of KIM-1 AKI to assist in the diagnosis of AKI after 24 h ,AUC was 0 .871 (95% CI:0 .665-0 .933);combined de-tection of urinary NGAL and KIM-1 levels to assist the best time for the diagnosis of AKI after 24 h ,AUC was 0 .913(95% CI:0 .745-0 .968) .Conclusion Urine NGAL and urine KIM-1 in children with congenital heart disease after operation have important clinical significance in predicting the occurrence of AKI .