The detection of HBV DNA in sera and leucocytes of 30 primary hepatocarcinoma patients whom were negative for HBsAg by reverse passive hemagglutination using polymerase chain reaction (PCR) were reported. The detectable rates of HBV DNA in leucocytes and sera were 86.7% and 70% respectively and the serological indexes, 43.4%. These indicated that HBV DNA may existent in blood of the patients with negative serological indexes. It was common that HBV DNA presented in peripheral leucocytes of primary hepatocarcinoma, indicated that extrahepatic sites of the HBV genome, and perhaps replication of HBV virus, existed. It was of great importance for the role of HBV DNA in lemology and epidemiology, etiology of hepatocarcinoma, diagnosis and treatment of infection as well as standard of cure.