Abstract: Objective To investigate the clinical value of PreS1 antigen detection in the diagnosis of chronic hepatitis B. Methods In 421 chronic hepatitis B patients,the PreS1Ag and HBV markers in serum were detected by ELISA,and HBV DNA by fluorescence quantitative PCR. Result The positive rate of PreS1Ag（51.2%） was higher than HBeAg（32.4%）in 367 HBV DNA positive chronic hepatitis B patients（P<0.01）;the positive rates of PreS1Ag in high（10⁵~10⁷ copies/ml and>10⁷ copies/ml,60.2% and 60.0%） were higher than in low serum HBV DNA load（10³~10⁵ copies/ml,41.9%） and in negative group（33.3%,P<0.01）;But in 421 patients,the positive rate of PreS1Ag（48.9%） was lower than HBV DNA（87.2%,P<0.01）. Conclusion PreS1Ag is more sensitive than HBeAg to reflect the HBV replication in chronic hepatitis B patients,but can’t replace the detection of HBV DNA.

Key words: Hepatitis B, PreS1 antigen, Hepatitis B virus markers