Objective To investigate the prevalence of duck hepatitis B virus(DHBV)in two farms. Methods A sampling survey of the duck species of domesticated Anas Platyrhynehos Linnaeus was carried out. 519 blood samples were collected from two farms in Heshun and Lishui towns of Nanhai city in Guangdong province,being from three categories,namely,newly-hatched,growing and full-grown ducks. The Dot Blot Hybredization measurement was to determine the DHBV prevalence. Results The average natural carrying rate of DHBV is 36.0%(187/519)from two farms. 95% confidence interval of the tested blood sample is within the range of 31.0%-44.0%. The differences of natural carrying rate of DHBV are nonsignficant for ducks of different ages,farms or sexes,while the differences of the values of optical density(A)of DHBV-DNA between ages are extremely significant(P<0.01),that is,the values decrease from newly-hatched to full-grown to growing ducks. The A values in Heshun farm samples are higher than Lishui. Conclusions DHBV carried by Anas Platyrhynehos Linnaeus from both farms may be probably derived from different sub-strains.