Objective To explore the relationship between serum cccDNA and liver damage in the patients with chronic HBV infection.Methods Serum cccDNA,ALT of 156 patients with chronic HBV infection were measured,and pathology of liver tissue in 85 patients was detected.Results The positive rate of Serum cccDNA and ALT had no significant difference(P>0.05).Between pathology light,medium and severe group,S0_(~1) and S_(2~4) group,G_(0~1) and G_(2~4) group the serum cccDNA mean was significantly different(P<0.01).The positive rate of serum cccDNA was significantly different between the group of NAASC and ASC,CH,LC,HCC,and the group of ALT ≤40u/Land 40~80,80~400,≥400u/L(P<0.01).Conclusion Serum cccDNA and liver inflammation,fibrosis and ALT had no relevance,serum cccDNA with at a low level may be non-active,but should be excluded from serious liver diseases.