Abstract: Objective To analyze and compare the viral replication in patients with hepatitis B virus( HBV) when serum markers HBe Ag and HBe Ab are both positive,or HBe Ag alone is positive,or HBe Ab alone is positive,or both are negative. Methods Electrochemiluminescence method was used to detect serum markers of HBV,and the samples with HBe Ag and HBe Ab being both positive,or HBe Ag alone being positive,or HBe Ab alone being positive,or both being negative were screened out,and the HBV DNA quantitative values of the samples were determined. Comparison of categorical data was made by chi- square test. Results Among 447 patients examined for serum markers of HBV,all were positive for HBs Ag. HBe Ag and HBe Ab were simultaneously detected in 32 cases,with a positive rate of 7. 16%. Of the 32 cases,84. 38% had HBV DNA levels of < 5 × 102 copies / ml,12. 50% had HBV DNA levels between 5 × 102 copies / ml and 1 × 104 copies / ml,and3. 13% had HBV DNA levels between 1 × 104 copies / ml and 1 × 107 copies / ml. The HBV DNA level of the HBe Ag / HBe Ab- positive group was significantly lower than that of the HBe Ag- positive group( χ2= 13. 21,P < 0. 01); the HBV DNA level of the HBe Ab- positive group was significantly lower than that of the HBe Ab- negative group( χ2= 74. 12,P < 0. 01). A total of 218 cases had negative HBe Ag,and 9( 4. 13%) of them had HBV DNA levels of >1 ×104copies / ml. Conclusion Being positive for both HBe Ag and HBe Ab is considered to be rare in the past; however,it is commonly seen clinically,and a proportion of patients have a relatively high level of viral replication. The viral replication weakens when HBe Ab appears. In cases of negative serum HBe Ag,some patients still show a high level of viral replication. Therefore,the presence or absence of HBe Ag cannot be regarded as the evidence in the assessment of antiviral efficacy and infectivity.