Abstract： Background Acute renal failure (ARF) after liver transplantation is associated with high mortality and morbidity. Early therapeutic or preventive intervention is hampered by the lack of early effective prognostic factors. Recent studies indicated that serum levels of cystatin C and β2-microglobulin (132 MG) as well as urinary β2 MG and N-acetyl-β-D- glucosaminidase (NAG) would increase in patients with early and mild renal impairment. In this study, these factors were detected during the different stages in patients who accepted orthotopic liver transplantation (OLT), and their feasibilities to predict early ARF after OLT were also analyzed.Methods Sixty patients with normal blood urea nitrogen (BUN) and serum creatinine (SCr) who received modified piggyback liver transplantation without veno-venous bypass were prospectively studied. Blood samples were drawn from patients for the determination of serum β2 MG(n=60), SCr (n=60) and serum Cystatin C (n=39) at following 5 intervals: before operation (TO), 20 minutes before anhepatic phase (T1), 25 minutes in anhepatic (T2), 60 minutes after repeffusion (T3) and at the end of operation(T4). Urinary β2 MG (n=-60) and NAG (n=60) were also examined at following 3 intervals: before operation (TO), 60 minutes after reperfusion (T3) and at the end of operation (T4). According to the Rimola A criteria of ARF in 24 hours after operation, all the patients were divided into two groups: ARF group and non-ARF group. The data were statistically analyzed to evaluate the feasibiliy of regarding these factors as prognostic factors for early ARF after liver transplantation in patients with normal SCr and BUN before operation.Results Ten of sixty cases showed ARF(16.7%). The Logistic regression analysis showed that the levels of serum and urinary β2 MG as well as serum cystatin C before operation were correlated with early ARF after liver transplantation (P <0.05), while only serum levels of cystatin C and Cr at the end of operation correlated with early ARF (P <0.05, P <0.01) after liver transplantation. The serum β2 MG, Cystatin C, SCr and urinary β2 MG levels in ARF group were much more higher than that in non-ARF group(P<0.05, P<0.01). There were significant differences between the correct and false predictive positive ratios of serum cystatin C, serum and urinary β2 MG levels before operation (P <0.05, P <0.01), while only SCr showed significant difference between these groups at the end of operation (P<0.01).Conclusions The results revealed that there was potential renal damage among those patients who demonstrated normal SCr and BUN before operation, and that liver transplantation could aggravate this damage and causing ARF. Here we provided the prognostic values of serum Cystatin C, β2 MG, urinary β2 MG and NAG in patients with early acute renal failure after liver transplantation.