In this paper we report on anti-HBc-titers, HBeAg, DNApolymerase activity in the serum and intracellular HBsAg in healthy HBsAg-carriers and patients with HBsAg-positive inflammatory liver diseases. 32/44 patients with acure virus-B-hepatitis were negative for anti-HBc in the first week of the disease. Anti-HBc-titers in healthy HBsAg-carriers varied between 1:10 and 1:32,000 (medium titer 1:4,000). In HBsAg-positive CAH we found a medium titer between 1:32,000 and 1:64,000, in cases with CPH of about 1:16,000. All autoimmune type CAH showed anti-HBc-titers less than 1:10. By immunofluorescence we could demonstrate in a group of 71 asymptomatic HBsAg-carriers in none of the healthy HBsAg-carriers HBcAg in the liver cell nuclei. In contrast HBcAg could only be found in 4/5 HBsAg positive CAH- and 6/9 CPH patients. No elevated DNApolymerase activity could be demonstrated in healthy HBsAg-carriers. Out of 44 patients with virus-B-hepatitis only 3 showed elevated DNApolymerase activity. On the other hand DNApolymerase elevation was demonstrable in 17/37 cases with CAH and 9/15 with CPH. The investigations showed a strong correlation between the demonstration of HBeAg in the serum and the DNApolymerase activity. The characteristic findungs enabled us to differentiate between healthy" HBsAg-carriers and HBsAg-carriers with inflammatory liver diseases. © 1978 Springer-Verlag."