Abstract: Objective To investigate the correlation of serum interleukin-1 receptor antagonist(IL-1RA) levels to outcomes of hepatitis B-related liver failure. Methods For the 31 hepatitis B-related acute-on-chronic liver failure patients,28 acute hepatitis B patients,30 chronic hepatitis B patients and 15 health controls,the serum IL-1ra and other six cytokines were measured by using Q-Plex.We further analyzed the concentrations of cytokines between death and survival HB-ACLF patients. Results The serum IL-1ra concentration was highest in patients with HB-ACLF[(338.9±268.8)pg/ml] when compared to those in AHB[(182.7±123.1)pg/ml,P=0.012],CHB[(77.07±40.5)pg/ml,P<0.001] and HCs [(37.9±15.6)pg/ml,P<0.001].However,the ratio of IL-1ra to IL-1β in patients with HB-ACLF(2.96±1.54) was lower than that in AHB patients(4.54±2.29),P=0.048.Serum IL-1ra in AHB patients was also higher than those in CHB(P<0.001) and HCs(P<0.001).Both IL-1ra(P=0.02) and IL-1ra/IL-1β(P=0.007) were lower in No-survivors than Survivors in HB-ACLF patients. Conclusion IL-1ra plays an important role in the development of HB-ACLF and is associated with outcome of HB-ACLF.