This is to evaluate the proportion of subjects who show good responses to LAM treatment in Korea.

This is to evaluate the proportion of subjects who show good responses to LAM treatment such as HBV DNA negativity, HBV DNA less than 4 log, no resistant mutation, HBeAg seroconversion and normalization of ALT in naïve CHB patients with certain pre-treatment characteristics, i.e. HBV DNA less than 9log copies per ml and ALT more than 2 times ULN in HBeAg positive subjects, HBV DNA less than 7log copies per ml and elevated ALT in HBeAg negative subjects.

Inclusion Criteria:

1. CHB or liver cirrhosis due to Hepatitis B virus who had started LAM between Jan 1, 2003 and Dec 31, 2004 and maintained LAM at least 6 months
2. HBsAg positive at least for 6 months at the beginning of observation
3. HBV DNA positive before LAM administration
4. Subjects with certain pre-treatment laboratory findings as follows; HBV DNA less than 9log copies per ml and ALT more than 2 times ULN in HBeAg positive patients, HBV DNA less than 7log copies per ml and elevated ALT in HBeAg negative patients

Exclusion Criteria:

1. Documented co-infection with HCV, HIV at the beginning of LAM treatment
2. Decompensated liver cirrhosis at the beginning of LAM treatment
3. HCC at the beginning of LAM treatment

CHB patients who started LAM as an initial antiviral treatment at least 5 years prior to this investigation in General Hospital