Abstract: Objective To observe the 3 month-efficacy of adefovir dipivoxil in the treatment of patients with lamivudine-related hepatitis B viral YIDD or YVDD mutant infection. Methods 30 lamivudine-resistant chronic hepatitis B patients were treated by combination of adefovir dipivoxil and lamivudine in this study for three months. The serum HBV DNA was detected by fluorescent quantitation PCR. Results The HBV YIDD or YVDD mutant infection was found in 21 patients,and the mixed mutant and wild viral infection was found in 9;the baseline of serum HBV DNA,ALT and AST in mutant group were 6.2±1.4 lgcopies/ml,139.8±153.2U/L and 119.0±32.1U/L,respectively. After 3 month treatment,they dropped to 2.3±2.3lgcopies/ml,54.5±44.7U/L and 39.8±32.1U/L,respectively;the baseline of them in mixed infection group were 6.0±1.9 lgcopies/ml,144.7±128.2U/L and 114.2±131.1U/L,respectively and after 3 month treatment,they dropped to 2.4±2.4lgcopies/ml,55.8±53.2U/L and 42.8±32.3U/L,respectively（P>0.05）;the HBV DNA loss in mutant infection was found in 90.5%,serum ALT normalization in 90.5%,and the HBV DNA loss and ALT normalization in mixed infection were 88.9% and 77.8%,respectively;no HBeAg seroconversion was found in mutant infection group,while 37.5%（3/8）had HBeAg seroconversion in mixed infection group. Conclusion Conbination of lamivudine and adefovir dipivoxil therapy for patients with hepatitis B mutant or mutants and wild viral infection can get the same short-term efficacy.

Key words: Hepatitis B, Lamivudine, Adefovir dipivoxil, Mutation