By radioimmunoassay, serologic markers of Hepatitis B Virus were studied in 44 patients with acute viral hepatitis, 10 patients with chronic persistent hepatitis, 10 patients with chronic active hepatitis, 44 patients with liver cirrhosis and 25 patients with primary hepatocellular carcinoma. The results were follows: 1) HBsAg was present in 77.2% of AVH, 40% of CPH, 80% of CAH, 55.1% of LC and 68% of PHC. In this HBsAg positive groups, all but one in liver cirrhosis had Anti-HBc. 2) Anti-HBs was most commonly detected in CPH and accompanied by Anti-HBc except one case in AVH. 3) Anti-HBc was the only marker detected in 11.4% of AVH, 20% of CPH, 20% of CAH, 16.3% of LC and 8% of PHC. 4) HBeAg was most commonly found in HBsAg-positive CPH but Anti-HBe was most frequently detected in PHC. 5) The absence of HBV markers was noted in 2.3% of AVH, 10% of CPH, 8% of PHC except CAH and LC.