Objective  To investigate the survival rate of patients with chronic severe hepatitis B (CSH) after lamivudine treatment.   Method  A matched retrospective cohort study using data on patients derived from a prospectively collected chronic severe hepatitis B database was conducted. The database included patients who received or did not receive lamivudine treatment from October

1999 to December

2003. The match was conducted according with 3 variables: sex

age and duration of disease. The match ratio was 1∶1. Cases were patients who received lamivudine treatment (n=103).Controls were patients who did not receive lamivudine treatment (n=103).  All the patients were followed up and their median survival time and survival rate were compared and evaluated.   Results  The median survival time in lamivudine treatment group and control group were 85 and 35 d respectively. The survival rate for 3 years in treatment group and control group were 42.7% and 23.4% respectively. There was significance difference in survival rate between the 2 groups (P0.01).   Conclusion  Lamivudine may improve survival of patients with chronic severe hepatitis B.