ObjectiveTo analyze hepatitis B virus (HBV) genotype distribution and drug-resistant mutations in West China Hospital of Sichuan University, providing basis for hepatitis B individualized treatment.MethodsA total of 786 chronic hepatitis B patients admitted to West China Hospital of Sichuan University from January 2016 to December 2018 were enrolled in the study. Genotype and drug-resistant mutations were analyzed by Sanger sequencing, and statistical analysis was conducted by χ2 test.ResultsThree genotypes (B, C and D) were identified in 786 samples, 489 (62.2%) in genotype B, 291 (37.0%) in genotype C , and 6 (0.8%) in genotype D. The distribution differences of B and C genotypes in age and ethnic groups were statistically significant (P<0.05). Among them, 627 cases had drug-resistant mutations, with a drug-resistant mutation rate of 79.8%. A total of 262 cases (33.3%) were resistant to lamivudine and tibivudine, 102 cases (13.0%) were resistant to lamivudine, tibivudine and entecavir; 83 cases (10.6%) were resistant to adefovir dipivoxil. No tenofovir resistant strains were detected in 786 samples. There were statistically significant differences in drug resistance between B and C genotypes (χ2=14.356, P<0.01). The most common single mutation was M204I [179 cases (22.8%)], followed by 46 cases (5.9%) of A181V/T associated with adefovir dipivoxil resistance. The most common mixed mutation was L180M+M204V/I in 83 cases (10.6%), and another 102 cases (13.0%) showed M250V and/or V173L and/or T184A/G/S/I and/or S202G/I with L180M+M204V/I.ConclusionsHBV genotypes in West China Hospital of Sichuan University are mainly B and C, and the situation of drug resistance is severe and the mutation pattern is complex. Therefore, detecting HBV genotype and drug resistance mutation is necessary, which may develop better clinical treatments.