Abstract: A fusion protein, Interferon-BLA (IFN-BLA), was constructed with IFN-beta-1b and IFN-alpha-2b separating by a linker –GGGS-. The laboratory-scale expression conditions in E.coli BL21 CodonPlus (DE3)-RIL had been optimized and IFN-BLA was expressed higher than 35% of total protein in the cells mainly as inclusion body. The inclusion body of IFN-BLA was denatured and refolded by dialysis and purified by ion-exchange chromatography. The overall yield of IFN-BLA was about 45 mg/L with purity higher than 90%. Antiviral activity assay suggested that this newly fused protein may have synergetic or additive antiviral activities.