According to the World Health Organization about 1,400,000 deaths reported annually, are related to chronic liver disease. Chronic liver disease is very prevalent in South Korea, placing a large economic burden nationwide. Subsequently, an effective and systematized approach to managing chronic hepatitis is imperative in Korea.

The natural history of chronic liver disease differs greatly according to race and ethnicity. However, there is scarcity of epidemic data on chronic hepatitis based on Korean patients. Therefore, the investigators plan to establish a prospective multicenter cohort for chronic hepatitis B based on Korean patients that may be utilized for various future clinical studies on chronic hepatitis B in Korea, and thereby serve as a basis for the establishment and distribution of clinical guidelines for Korean patients with chronic hepatitis B, as part of a nationwide project supported by the Centers for Disease Control (CDC), Korea.

The investigators plan to collect more than 2,000 cases per year with 6 months of regular follow-up interval as have been advised by the CDC during 10 years of the study period (from Sep. 2015) from 5 tertiary hospitals located in Korea. The investigators plan to register available cases from those who are available to agree to give written informed consent and provide their blood samples to participate in this study prospectively, according to the inclusion and exclusion criteria.

Inclusion Criteria:

1. age above 19 years;
2. CHB diagnosis with more than 6 months of HBsAg positive;
3. Patients who followed up regularly by medical institutions due to CHB;
4. Patients who can be followed up according to the research protocol;
5. Patients who have consented to the written consent of the applicant or guardian.

Exclusion Criteria:

1. HCC diagnosis before enrollment;
2. Malignant tumor other than HCC within 5 years;
3. Hepatitis C virus or human immunodeficiency virus co-infection;
4. Fatal conditions such as decompensated liver function, end stage renal disease and severe heart failure;
5. not be suitable for the research purpose.

Outpatient clinic in tertiary hospitals

The patients' clinical and laboratory information are stored in the Korean CDC database as a form of eCRF, then be locked after data cleaning. The sharing data will be coded and won't include patients' sensitive individual information such as a unit-ID and name. The coded data and saved samples will be provided for the guaranteed researchers by the government after confirmation of the relevance of their clinical and basic researches plan related with HBV, during the study and after the study ends.