Objective To explore the accuracy and clinical application of pyrosequencing for detection of drug resistant relevant mutation in the polymerase gene of hepatitis B virus(HBV).Methods Compared with Sanger sequencing,the accuracy and sensitivity of pyrosequencing were assessed.Pyrosequencing was used to determine the serum of 1 164 patients with chronic Hepatitis B and its re-sults were analyzed.Results The sensitivity of pyrosequencing was 1×103KIU/L,the same as Sanger sequencing.But Objective To explore the accuracy and clinical application of pyrosequencing for detection of drug resistant relevant mutation in the polymerase gene of hepatitis B virus (HBV). Methods Compared with Sanger sequencing, the accuracy and sensitivity of pyrosequencing were assessed. Pyrosequencing was used to determine the serum of 1 164 patients with chronic Hepatitis B and its re-sults were analyzed. Results The sensitivity of pyrosequencing was 1 × 103KIU / L, the same as Sanger sequencing.But