To understand the serotypes of RA in Taiwan, 277 strains of goose isolates and 294 strains of duck isolates from Poultry Health Medical Center were determined their serotypes by slide agglutination test
during August 2004 to September 2007. In goose isolates, serotype 2 (19.9%), serotype 1 (15.9%) and serotype 12 (8.7%) were most prevalent and 30.3% isolates were untypable. In duck isolates, serotype 2 (26.2%), serotype D (15.9%) and serotype 12 (12%) were most prevalent and 23.8% isolates were untypable. In combination of 571 isolates from goose and duck, serotype 2 (23.1%), serotype 12 (10.3%) and serotype D (9.3%) were most prevalent and 26.9% isolates were untypable. According to the results, there were at least 16 serotypes of RA in Taiwan. These results could be applied to control the outbreaks of RA infection in Taiwan.