Abstract: Objective To detect HBV cccDNA in serum and peripheral blood monouclear cells in patients with chronic hepatitis B. Methods 95 patients with hepatitis B and 8 with liver transplantation were investigated. HBVcccDNA was detected by using synergy PCR technique. Results We did not detect positive HBV cccDNA in peripheral blood monouclear cells in any patients of our series;the serum positive rates of HBV cccDNA in 20 HBV carriers,in 75 patients with chronic hepatitis B of mild,middle and severe degree and in 8 after liver transplantation were 10%,32%、52% and 76%,and 12.5%（P<0.01）;in patients with serum HBV DNA at<1×10⁵ copies/ml,1×10⁵~10⁸ copies/ml and>1×10⁸ copies/ml,their serum HBVcccDNA positive rates were 15.4%（2/13）,50.0%（16/32）and 76.7%（23/30,P<0.01）. Conclusions HBV cccDNA do exist in sera,but not in peripheral blood monouclear cells in patients with chronic hepatitis B.

Key words: Hepatitis B, Covalently closed circle DNA, Polymerase chain reaction, Peripheral blood monouclear cells