This study is an open-label, multicenter, PCR response adaptive clinical study design, with intensification of treatment (addition of adefovir to telbivudine treatment) depending on HBV DNA level at week 24. All patients commence with Telbivudine 600mg daily. At week 24 they will be divided into 2 Groups according to virological response. Patients with PCR detectable HBV DNA will add on ADV(Group I). Patients with PCR undetectable HBV DNA(Group II)will continue telbivudine monotherapy. ADV will not be added on unless viral breakthrough occurs.