Acute kidney injury (AKI) is associated with high incidence and mortality rates, and leads to great economic and health-care burdens. Early assessment, diagnosis and interventions as soon as possible are important factors affecting the prognosis of patients with AKI. Identifying high-risk groups, avoiding exposure factors, supplementing adequate body fluids, and closely monitoring changes in serum creatinine and urine output are key elements of prevention and early identification of AKI. We reviewed recently published clinical guidelines and important literatures, from definition, risk assessment, new biomarkers for early diagnosis, and finally to discuss the current concept of treatment. As for dialysis therapy in patients with AKI, we once again emphasize the concept of "renal support" rather than "renal replacement" to reduce the load on other organs.