Abstract: Livers of diseased ducks in Beijing district were made disease materials. Disease materials were inoculated in 9 to 11 days chicken embryo allantoid cavity. The results showed that isolation virus strains made chicken embryo stunt, embryo claws grew abnormality, livers of chicken embryo became green. Animal test indicated that the death rate of ducks of 2 days were 100% during 2 or 3 days, and clinical symptoms and pathological changes were consistent with nature disease ducks after inoculating the virus. Isolation virus strains isn,t susceptible to chloroform and CPE isn,t obvious through inoculating embryo fibre cells. Blood serum test proved that the serotype of the virus was the typeⅠand virulence was very strong.

Key words: duck; hepatitis virus; isolation; identification