In an attempt to clarify the relationship of liver cirrhosis and hepatocellular carcinoma, we have carried out investigations at an area where both these diseases develop frequently. 1) We studied the incidence of HBsAg and its antibody in 3521 inhabitants of Tomié-Town in the Goto Islands; 5.5% proved to be positive for HBsAg and 22.0% positive for anti-HBs. 2) In the HBsAg-positive group, the incidence of hepatomegaly and abnormal liver function were significantly higher than those in other groups. 3) In relation to HBsAg, anti-HBs and histological abnormalities of the liver, positive HBsAg was detected in one subject with hepatocellular carcinoma associated with liver cirrhosis, six of nine with liver cirrhosis, and four of 11 with chronic hepatitis. A positive antibody was found in one subject with liver cirrhosis and four with chronic hepatitis. Thus, HB virus infections was closely associated with latent liver disease in Tomié-Town.