A novel gene encoding the alpha-chain of goose immunoglobulin heavy-chain (Ig alpha) was cloned by reverse transcription-PCR. The cDNA had 1,760 bp and encompassed a partial V-D-J region of the heavy chain, a constant region (C alpha) and 3'-untranslated region of alpha-chain. The C alpha gene contains four constant region domains (CH1-CH4). Phylogenetic analysis indicated that goose IgC alpha has a close genetic relationship with duck, ostrich and chicken IgC alpha. Three-dimensional modeling and glycosylation analysis revealed the goose Ig alpha is consistent with the characterization of immunoglobulin. Western blotting suggested the goose IgC alpha has the same antigenicity to natural IgA. In general, the identification of goose immunoglobulin not only provides insights into the evolution of the Ig heavy-chain gene family, but may also benefit future studies of the avian immune system.