In the past decades, the incidence of acute kidney dysfunction has been steadily increasing, which is mainly due to rises in the prevalence of cardiovascular diseases and the survival of cardiac patients and to more common use of intervention examination and treatment methods. The early diagnosis of acute kidney injury (AKI) is made difficult by the delay in clinical symptoms and the elevated serum levels of creatinine as to cell damage, which chiefly appears as the expression of biomarkers. The new AKI biomarkers whose concentration changes significantly earlier than the serum creatinine levels increase have been recently identified. This has allowed Acute Dialysis Quality Initiative (ADQI) experts to develop consensus on the use of the biomarkers to diagnose AKI; a new concept of the diagnosis of AKI, by assessing not only the markers of renal function (serum creatinine and diuresis), but also those of injury, and the conceptual model of AKI are proposed.