Abstract： Objective To explore seroprevalence of hepatitis B markers among people 1-69 years of age in Xizang Autonomous Region in 2020.Methods We selected 1-69-year-olds from five disease surveillance points in Xizang using a multi-stage cluster random sampling method.We collected serum samples to test for hepatitis B surface antigen(HBsAg),surface antibody(HBsAb),and core antibody(HBcAb)using enzyme-linked immunosorbent assay,and hepatitis B e antigen(HBeAg)and e antibody(HBeAb)of HBsAg-positive samples using microparticle immunosorbent assay.We calculated positivity rates and patterns of the hepatitis B virus(HBV)markers.Results Among the 4 912 subjects,HBsAg,HBsAb,and HBcAb positivity rates were 9.20％,37.11％,and 32.76％(adjusted:8.65％,37.30％,and 30.35％),respectively.In 1-4-,5-14-,15-29-,and 30-69-year-olds,HBsAg positive rates were 2.23％,2.85％,6.87％,and 12.46％;HBsAb positive rates were 52.79％,32.67％,37.71％,and 36.03％;HBcAb positive rates were 4.19％,6.42％,21.09％,and 46.95％.Thirteen HBV marker combinations were detected.Subjects who were negative to all five markers,positive to only HBsAb,positive to HBsAg+HBcAb+HBeAb,and positive to HBsAg+HBcAb+HBeAg accounted for 43.79％,22.39％,6.15％,and 1.65％of subjects.Conclusions HBsAg seroprevalence,which indicates HBV infection,declined significantly among people aged 1-69 years,especially children,in Xizang in 2020,but a susceptible population remains.We still need to strengthen timely and full-series hepatitis B vaccination of newborns.