Interferon beta (IFN-beta) belongs to a class of natural proteins that can inhibit virus replication. In this paper, nucleic acid sequence encoding chicken interferon beta (chIFN-beta) mature protein was cloned and highly expressed in Escherichia coli (E. coli) by 1 mM IPTG induction. The expressed chIFN-beta was about 20% of total bacterial protein. The recombinant protein in form of inclusion body was then solubilised, refolded and purified to a purity of greater than 95% by immobilized metal ion affinity chromatography (IMAC). This recombinant chIFN-beta could inhibit vesicular stomatitis Indiana virus (VSV) and infectious bursal disease virus (IBDV) replication in vitro. Animal experiments showed that the recombinant chIFN-beta could decrease pathological lesions caused by the IBDV in bursa of Fabricius. These results will provide useful information for further investigations on veterinary clinical applications and fundamental research. (c) 2012 Elsevier Inc. All rights reserved.