Abstract: In order to express the recombinant chicken α-interferon（IFN-α） with antiviral activity, according to the codon preference of Escherichia coli, the mature peptide gene sequence of chicken IFN-α was optimized. After synthesis, it was connected to the prokaryotic expression vector pET30 a-ELP and induced in vitro to express the recombinant protein ELP-ChIFN-α. Purification was carried out by means of repeated reversible phase transition cycles（ITC） method; the purified protein was denatured and renatured for safety evaluation. The antiviral activity of the protein was detected in the canine kidney cell（MDCK）/Vesicular stomatitis virus（VSV） system by the microcytopathic inhibition method. The results showed that the synthesized recombinant chicken IFN-α mature peptide gene was successfully expressed in the prokaryotic expression system, and the cell growth inhibition rate of recombinant protein ELP-ChIFN-α at different concentrations was 0. The recombinant protein ELP-ChIFN-α had antiviral activity in the MDCK/VSV system, with an activity of 1.2×10~6 IU/mg. The results suggested that the recombinant chicken IFN-α expressed in prokaryotic had good antiviral activity, and could be used as an antiviral biological drug in chicken for further development and research.