To explore HBV infection status in a group of serologic HBV markers-negative or HBsAg-negative patients with chronic hepatitis, in situ hybridization to hepatocellular HBVDNA was carried out in combination with detection of HBsAg and HBcAg in the liver tissues. It was found that prevalence of intrahepatic HBVDNA, HBsAg and HBcAg was 43%, 39% and 17% respectively, and 15 out of 23 cases studied were sure to bear one or more positive marker(s) of intrahepatic HBVDNA, HBsAg and HBcAg. These findings suggest that more than half of the patients with chronic hepatitis were still undergoing HBV infection, despite serologic HBV markers or HBsAg negative. Furthermore, we found that hepatocytes containing HBVDNA or surface or core antigen were often close to hepatic necrosis foci, indicating that HBV replication and its antigen(s) expression in hepatocytes could account for chronic, active and necrotic inflammation occurring in the liver of the patients mentioned above.