Update publication information. The incidence of CI-AKI varies from 5% to 20% among hospitalized patients. However, research on the pathophysiological mechanism and biomarkers of CI-AKI has not been deep so far, especially research with LC-MS/MS methods. MS has brought proteomics research into the modern era and continues to be the best choice for accurate medicine. Thus, we identified the urine proteins of CI-AKI patients with LC-MS/MS methods and compared the differences in urine protein expression between CI-AKI patients and non-CI-AKI patients with bioinformatics analysis. Several DEPs were identified in CI-AKI patients, some of which are related to kidney diseases, including annexin A2 (ANXA2), growth differentiation factor 15 (GDF15) and retinol-binding protein 4 (RBP4). We think that they are likely to be biomarkers of CI-AKI. Among the DEPs, we found that the number and degree of proteins expressed in tubules were more significant than those in glomeruli, which indicated that tubule injury may play a more important role in CI-AKI. Through bioinformatics analysis, we found that the immune response and inflammation were involved in CI-AKI, which indicated that the immune system and inflammatory response may participate in CI-AKI progression. Our study revealed some proteins that are likely to be biomarkers and provided a further understanding of CI-AKI.