The purpose of this study is to evaluate the safety, tolerability and antiviral efficacy of telbivudine by maintained suppression of hepatitis B virus (HBV) DNA (<=300 copies/ml or 60IU/ml, undetectable by current polymerase chain reaction (PCR) - based assays) in HBeAg positive/negative patients at physician's general practice.

Primary objective: To evaluate the antiviral efficacy of telbivudine by maintained suppression of HBV DNA(<=300 copies/ml or 60 IU/ml,undetectable by current PCR-based assays) in HBeAg positive patients from Week 24 to Week 48.

Methodology: This will be an open-label, prospective, observational, single-center and single arm post marketing surveillance study.

Number of patients: It is estimated to enroll 240 intent-to-treat patients in Taiwan.

Population: Male or female patients, at least 18 years of age diagnosed with chronic hepatitis B with liver disease and telbivudine is prescribed by physicians based on clinical justification. And patients are able to communicate well, provide written informed consent, and willing to participate in the entire study.

Inclusion Criteria:

1. Male or female, at least 18 years of age.

2. Documented chronic hepatitis B defined by all of the following:

   • Clinical history compatible with chronic hepatitis B.
   • Detectable serum hepatitis B surface antigen >= 6 months at screening visit, with either HBeAg positive or negative.

3. Willing and able to comply with the observational drug regimen and all other study requirements.

4. Willing and able to provide written informed consent to participate in the study.

Exclusion Criteria:

1. Females who are pregnant,intending to become pregnant or breast feeding.
2. Patients with co-infection with hepatitis C virus, hepatitis D virus or human immunodeficiency virus.
3. Patients with hypersensitivity to telbivudine or to any of the excipients.
4. One or more known primary or secondary causes of liver disease other than hepatitis B (e.g., alcoholism, steatohepatitis, autoimmune hepatitis, hemochromatosis, alpha-1 anti-trypsin deficiency, Wilson's disease, other congenital or metabolic conditions affecting the liver, congestive heart failure or other severe cardiopulmonary disease). Gilbert's syndrome and Dubin-Johnson syndrome will not exclude patients from participation in this trial.
5. Enrolled or planning to be enrolled in another clinical trial of an investigational agent while participating in this study.
6. Unable to receive safety and tolerability assessments.

Male or female patients, at least 18 years of age diagnosed with chronic hepatitis B with liver disease and telbivudine is prescribed by physicians based on clinical justification. And patients are able to communicate well, provide written informed consent, and willing to participate in the entire study.