Background: To investigate the relationship between hepatocyte apoptosis and the level of inducible nitric oxide synthase (iNOS) in hepatic tissue in the patients with chronic hepatitis B CHB . Methods: we observed 37 cases with CHB and 10 normal controls. Transferase-mediated-UTP-biotin nick-end labling ( TUNEL) technique was used to detect apoptosis cells and immunohistochemical staining were also performed to investigate the expression of inducible nitric oxide synthase (iNOS) in biopsy samples .The serum level of ALT HBV-DNA grading of necroinflammatory activity and staging of fibrosis were also assessed. Results: Hepatocytes in all CHB liver tissues were positively stained by TUNEL in various degree. In contrast, control tissues did not show DNA fragmentation. A significant correlation was seen between apoptosis index (AI) and necroinflammatory grading ((r=0.404, P=0.015) and serum iNOS level r=0.465, P=0.004 . It did not correlate with fibrosis stage and serum alanine aminotransferase level. Conclusion: The oxidative stress.in patients with CHB may reflected the apoptosis of hepatocyte. Apoptosis involves in liver injury of CHB,but with no significant correlation to serum level of ALT. Objectives: To investigate the genotype-dependent development of lamivudine resistance in hepatitis B virus (HBV). Methods: 215 patients with chronic hepatitis B who had been treated with lamviudine for more than 1year, and become lamviudine resistance were analysed for the HBV genotypes and cumulative rate of RT region mutant with standard DNA sequencing technology. Results: Among the 215 patients, 60 patients were infected with HBV genotype B (HBV/B)(27.9%), and 155 with genotype C (HBV/C)(72.1%). In the HBV/B patients, 16/60(26.7%) were of subtype Ba, and 44/60(73.3%) were of of subtype Bj. The cumulative type and YMDD mutation rates in patients with genotype C were showed as L180M+M204V (67/155,43.2%) > L180M+M204I (52/155,33.5%) > M204I (36/155, 23.3%), while in patients with genotype B as L180M+M204V 36/60(60.0%) > M204I(24/60, 40.0%), none of L180M+M204I. Conclusions: Our results indicated that in patients with lamivudine resistance, HBV genotype C (HBV/C) were higher than genotype B (HBV/B). In both genotypes the combined mutations (180+204 sites) were found more than the single 204 site, showed some significance for monitoring lamivudine resistance. 