The cDNA of goose interferon-alpha (goIFN-alpha) was amplified from PHA stimulated PBMCs of goose by RT-PCR. The cDNA encodes a 30-amino acid signal peptide and a 161-amino acid mature protein, respectively. Recombinant mature goIFN-alpha (rgoIFN-alpha) expressed by prokaryotic and eukaryotic system possessed antiviral activity that was neutralized by rabbit anti-rgoIFN-alpha antibody in vitro. On the other hand, rgoIFN-alpha lacks intrinsic macrophage activating factor (MAF) activity, peripheral blood leukocyte-derived macrophages (PBLMs) could not produce nitric oxide (NO) by stimulate with rgoIFN-alpha as compared to stimulate with recombinant mature goIFN-gamma (rgoIFN-gamma) that was a powerful NO stimulant in vitro.