This study will evaluate the safety and immunogenicity of a novel mixed plasmid DNA (HB-110) combined with an antiviral agent (Adefovir) for the patients with chronic Hepatitis B infection.

Inclusion Criteria:

• Chronic hepatitis B infected patient documented with positive HBsAg for 3 months and more at screening
• Chronic hepatitis B infected patient with positive HBeAg at screening
• Patient who has not treated with interferon alpha, lamivudine or adefovir within 3 months before study entry
• HBV DNA more than 1x10^5 copies/mL through COBAS Amplicor HBV monitor assay or bDNA method at screening
• Patient with HBV DNA decrease more than 10-fold compared to the baseline after 8 weeks treatment with adefovir
• Patient with ALT value between ULN x 1.5 and ULN x 5 at screening
• Patient given a written consent voluntarily

Exclusion Criteria:

• Have uncompensated liver disease
• Serum creatinine > ULN x 1.5
• Are positive for Hepatitis C, hepatitis D or HIV infection (confirmed by ELISA assay)
• Had a previous liver or bone marrow transplant
• Are currently taking any immunosuppressant or any possible immune modulatory drugs
• Women who are pregnant or breastfeeding
• Woman or man who plans a birth for study duration
• Any experience of severe adverse drug reaction or any medical history of severe allergic disease
• Patient with any severe disease (for example, heart failure, renal failure, pancreatitis, diabetes mellitus) affecting the study in discretion of investigator except liver disease
• Patient with any other liver disease but hepatitis B (for example, hemochromatosis, Wilson's disease, alcoholic/non-alcoholic liver diseae)
• Patient with intrahepatic tumors confirmed by imaging (liver biopsy)and abnormally increased alpha-fetoprotein
• Patient with any present malignant tumor except liver or its history
• Other inappropriate patient in discretion of investigator