The Efficacy of Adefovir Dipivoxil against All Patterns of Lamivudine Resistant Hepatitis B D.J. Kim 1 , Y.D. Park 1 , Y.G. Kwon 2 , H.G Seo 1 1 Daegu Fatima Hospital, 2 Kunngpook National University Hospital, Daegu, Korea Background: Our aim was to evaluate the efficacy of adefovir dipivoxil (ADV) and determine patient-dependent or laboratoroy variables that are predictive of HBeAg loss and IVR for hepatitis B patients resistant to lamiduvine. Also we evaluated the activity of ADV against all patterns of lamivudine-resistant HBV. Method: 179 HBV-infected patients with lamivudine resitance received ADV for 6 months. Quantitative HBV DNA, HBeAg/anti HBeAg, ALT was checked every 3-6months. The HBV polymerase of 161 patients were sequenced for baseline samples to determine the presence of lamivudine resistance mutations. Result: There is no significant difference in all patterens of HBV mutation about HBV DNA reduction at 24W, 48W, 72W. There is no significant difference in all patterens of HBV mutation about ALT normalization at 24W, 48W, 72W. Conclusion: Adefovir dipivoxil demonstrated similar potent anti-HBV efficacy regardless of the different patterns of lamivudine-resistant HBV mutations.