Abstract: Objectives　To investigate the association of the acute kidney injury (AKI) biomarkers (Cys C, KIM-1, and NGAL) with the diagnosis and prognosis of septic AKI. Methods　Ninety-two children with sepsis from April 1, 2011 to July 31, 2011 were recruited. According to the 48 h serum creatinine level after hospitalization, the children were divided into septic AKI group (32 cases) and septic non-AKI group (60 cases). The Cys C, KIM-1, and NGAL levels were comparatively analyzed to assess their abilities to diagnosis and predict the prognosis of septic AKI. Results　At 2 h after hospitalization, the levels of serum creatinine, serum urea nitrogen, serum Cys C, urine KIM-1, serum NGAL, and urine NGAL were significantly higher in septic AKI group than in septic non-AKI group (P<0.05). At 48 h after hospitalization, except the urine KIM-1, the levels of other biomarkers were still significantly higher in septic AKI group than in septic non-AKI group (P<0.05). On 7 d after hospitalization, except the serum creatinine, the levels of other biomarkers were no significant difference between two groups (P>0.05). The AUCs of serum Cys C, urine KIM-1, serum NGAL, and urine NGAL at 2 h after hospitalization were larger than that of serum creatinine and also larger than each of AUCs at 48 h after hospitalization in the diagnosis of septic AKI. The serum Cys C, urine KIM-1, serum NGAL, and urine NGAL level can be used to predict the prognosis of septic AKI. Conclusions　Cys C, urine KIM-1, serum NGAL, and urine NGAL can be used as early biomarkers to diagnose and to predict the prognosis of AKI. All of biomarkers are positively correlated with serum creatinine level at 48 h hospitalization.