Abstract: Anti-virus treatment has been cousidered as an important measure for HBV infection and guantitative assay of HBVDNA was needed for evaluating therapeutic effects. Blood, liver, spleen, kidney and brain tissues were arbitrarily collected from HBV infected patients for HBVDNA quantitative assay. The positive rate and mean concentration of HBVDNA in blood and liver tissue were comparatively low in acute hepatitis patients, but in chronic cases, both were obviously higher than that of acute cases. Most cases had hepatocell-conversion of HBVDNA at serocon-version of HBVDNA after treatment except a few cases with very low titer. The HBVDNA could be detected in blood. liver, spleen, kideny and brain tissues of chronic HBV infected cases and the positive rates and quantity of HBVDNA of visceral tissues were obviously higher than that of blood. So, consolidating treatment cauld not be neglected for the cases having had seroconversion of HBVDNA might come later owing to higher quantity for avoiding relapse.