Abstract: This experiment isolated 19 strains Streptococcus successfully from the internal organs of disease duck used blood agar and nutrient agar culture medium. We can see gram positive coccus array like catenuliform through microscope after Gram staining. Biochemical test and animal inoculation test showed that the isolated bacteria are pathogenic to duck. Drug sensitive test showed that the drug resistance of isolated streptococcus is very high. Twelve strains Streptococcus is low sensitive or not sensitive to Amikacin, Cefatriaxone, Ofloxacin so on fourteen medicaments except seven strain Streptococcus is middling sensitive to Amikacin. This indicates that the enhancing drug resistance of duck streptococcus makes it hard to prevention and cure of duck Streptococcus disease.

Key words: duck; Streptococcus; isolation; drug resistance