The purpose of this clinical research study is to assess the safety effectiveness of entecavir, as compared to lamivudine, in the treatment of adults with chronic hepatitis B infection who are hepatitis B e antigen positive.

• Male and female subjects =/> 16 years of age (or minimum age required in a given country) with history of chronic hepatitis B infection;
• Documentation of positive Hepatitis B e antigen (HBeAg) status.;
• The absence of coinfection with immunodeficiency virus (HIV), hepatitis C virus (HCV) or hepatitis D virus (HDV);
• The absence of other forms of liver disease e.g., alcoholic, autoimmune, biliary disease;
• Less than 12 weeks prior therapy with nucleoside or nucleotide analogue antiviral agents with activity against hepatitis B (e.g., adefovir, famciclovir and lamivudine)