Acute kidney injury(AKI) is a series of clinical syndromes caused by acute loss of kidney func-tion in a short time(several hours or several days) due to various reasons.There are great difficulties in diagno-sing and treating acute kidney injury due to lack of early sensitive and specific biomarkers.This article describes early biomarkers of acute kidney injury such as Cystatin C(Cys C),neutrophil gelati-associated lipocalin(NGAL),kidney injury molecule 1(KIM-1) and explores their value for early diagnosing acute kidney injury,supplies evidence for evaluating renal function,giving early treatment and prognosis for acute kidney injury.This review summarizes the recent literature on these biomarkers.