ObjectiveTo study the relationship between HBV genotypes and nucleolide analogues drugresistance mutations. MethodsOne hundred and twentytwo patients with chronic hepatitis B were treated with lamivudine 100mg/d for 48~96 weeks, patients who developed lamivudineresistance mutations used  adefovir dipivoxil  10mg/d for 96 weeks instead of lamivudine. HBV genotypes, lamivudine, adefovir dipivoxil and entecavir resistance mutations were determined by DNA  sequencing. ResultsAmong  122 cases, 86 (70.49%) were genotype B, 24 (19.67%) were genotype C, and 12(9.84%) were not classified. 42 lamivudineresistance mutants (32 mutants of genotype B, and 10 mutants of genotype C) were found in 122 cases. The incidence of mutations was 37.21%(32/86)  and 41.67%(10/24) in HBV genotypes B and C, respectively,there was no significant difference between the two (χ2=0.16,P=0.69). The incidence of mutations was 0.00%(0/42) and 2.38%(1/42) in 42 patients treated  with adefovir dipivoxil for 48 and  96 weeks, respectively, the incidence of adefovir dipivoxil mutations  was 3.13%(1/32) and 0.00%(0/10) in genotypes B and C, respectively. The  main types of lamivudineresistance mutations  were rtM204V+rtL180M(35.71%) and rtM204I(38.10%);  Lamivudineresistance mutation types showed no significant difference between HBV genotypes B and C(χ2=17.44,P=0.23). ConclusionHBV genotype B is the most prevalent, and genotype C is the second in Hengyang of  Hunan. HBV genotypes have no obvious influence on the incidences and types of mutation during lamivudine therapy.