Aims: To establish a reliable real-time fluorescence quantitative (RFQ) PCR method to quantify HBV cccDNA, basing on LightCycler system and Taqman probe. Methods: HBV genotypes A-G were aligned to obtain a conserved sequence, crossing rcDNA gap, which was used to design cccDNA primers and Taqman-MGB probe. Also another pair of primers for quantify HBV total DNA (tDNA) was designed, utilizing the same probe. To increasing specificity, we added plasmid-safe ATP-dependent dnase (PSAD) digestion step just before cccDNA PCR amplification. A standard curve from 9 standard plasmid samples, from 2.0×10 9 to 2.0×10 1 copies, was created to examine our system. 50 HBV cccDNA samples with known-amount were quantified by creating standard curve from 5 standard samples. Results: The standard curve had clear log-phase and excellent parallelism, which means nice and equal amplification efficiency in all reaction capillarys. The slope (regression coefficient) of standard curve was -3.141, mean square error was 0.0990 and regression coefficient was -1.0. All of these key indexes measured up. In 50 tests, we got right results if the starting templates of cccDNA copies were between 10 2~1 0 9 copies. The range was superior to commercial HBV kits. By quantifying 16 samples containing different amounts of cccDNA and rcDNA, digested or undigested, PSAD digestion would eliminate 10 7 rcDNA molecules, leaving 10 2 cccDNA molecules untouched. The test specificity was maintained up to 1:100,000 ratio of cccDNA:rcDNA. Conclusions: The RFQ-PCR based on LightCycler system for HBV cccDNA quantification is reliable, sensitive, with high specificity and low cost. Background: To study the changes of Toll-like receptor (TLR)3 on dendritic cells derived from peripheral blood mononuclear cells(MoDC) and its role in the pathogenesis of chronic hepatitis B(CHB) and chronic severe hepatitis B(CSHB). Methods: The expressions of TLR3 on 10000 MoDC were stimulated by poly I:C, and then were determined by flow cytometry in 20 healthy controls, 28 patients with CHB and 30 patients with CSHB.The level of interferon IFN-was determined by ELISA. The differences of expression of TLR3 on MoDC and serum IFN-among the three groups of study subjects were determined by student-t test.The correlation between TLR3 and IFN-were determined by linear correalation test. Results: The values of mean fluorescence intensity(MFI) of TLR3 on MoDC of the healthy controls, patients with CHB and CSHB were 1593.00±349.65,1369.56±287.08,and 1203.96±192.40.The serum IFN-(pg/L) of respective groups was 172.66±37.96,107.98±31.15 and 72.06±29.58. There was a gradual decrease of these values from the group of healthy controls to the group of patients with CHB and CSHB .Significant positive correlations between TLR3 and serum IFN-were found. Conclusion: TLR3 may have a role in the pathogenesis of CHB and CSHB.