【Objective】 To investigate the effect of pretreatment liver failure degree on the outcome of patients with HBeAg-negative acute-on-chronic liver failure (ACLF) lamivudine treatment. 【Methods】 A total of 71 patients received lamivudine plus basic medical treatments. Their serum HBV DNA loads and MELD scores were statistically analyzed at pretreatment

post-treatment or death before. And the survival rates of different MELD scores ranges were compared. 【Results】 25 patients had pretreatment MELD scores above 31

whose MELD scores of pretreatment and before death were 33.97±3.59 and 38.89±9.29

respectively. Meanwhile

HBV-DNA loads were 5.58±1.86 and 3.56±1.05 log10 copies/mL in order. For 27 patients with pretreatment MELD scores ranged from 23 to 31

their MELD scores increased from 25.45±2.63 to 29.65±9.90 while HBV-DNA loads decreased from 5.53±1.83 to 3.23±1.07 log10 copies/mL after treatment. MELD scores decreased from 19.54±1.96 to 15.66±7.98 and HBV-DNA loads decreased from 6.34±1.63 to 3.11±0.97 log10 copies/mL in 19 patients with pretreatment MELD scores below 23. In each group

there were significant differences in MELD scores and HBV DNA loads between pretreatment and post-treatment statistically (P<0.05). Among three groups，no significant difference was found in HBV DNA loads at pretreatment and post-treatment (P>0.05). The survival rates were 8.00% (2/25)

55.56％(15/27)

and 84.20% (16/19) in sequence and there were significant differences (P<0.05). 【Conclusions】Pretreatment liver failure degree significantly affects the outcome of lamivudine plus basic medical treatment on patients with HBeAg-negative ACLF. For patients with pretreatment MELD score above 31

the survival rate is low.