Abstract: Objective To investigate the clinical efficacy of Telbivudine in the treatment of chronic severe hepatitis B.Methods 60 patients with chronic severe hepatitis B were randomly divided into 2 groups.The control group (n=30) was given conventional therapy, while the treatment group treated with telbivudine, 600mg daily, on the basis of routine.Before and after treatment for 2, 4, 12 weeks, the level of HBV DNA of the two groups were detected, and hepatic function and PTA measured on the forth week.The efficacy of treatment at the forth week was evaluated.Results HDV DNA negative conversion rate of 33% (after 2 weeks) , 80% (after 4 weeks) and 83.3% (after 12 weeks) in treatment, that was significantly higher than those in control group (0 after 2 weeks, 3.3% after 4 weeks, and 10% after 12 weeks) (P <0.01) .After treatment for 4 weeks, the improvement of TBil and PTA in treatment group were much better than those in the control group (P<0.01) , The total effective rates of treatment group and control group were 67.7% and 40% (P<0.05) .Conclusion Telbivudine had an strong anti-HBV activity, and a rapid effect.It will significantly improve the hepatic function for patients with severe hepatitis B.