Both interleukin-1 and IgE are important in the pathogenic mechanism of the allergy asthma. cDNA of interleukin-1receptor antagonist (IL-1ra) and IgE were cloned and a prokaryotic expression vector IL-1ra-Fcepsilon/pBV220 was constructed. The vector was transformed into Escherichia coli BL21(DE3). The fusion protein was expressed successfully in the form of inclusion body. The recombination protein of IL-1ra-Fcepsilon was highly purified by chromatography of gel filtration and ion exchange, which was identifited by Western blotting. The cell assay showed that the activity of IL-1ra-Fcepsilon was as high as IL-1ra in vitro after refolding. The pharmacokenetic profile of IL-1ra-Fcepsilon and L-1ra was analyzed, and the half time of IL-1ra-Fcepsilon is 4.78 times than that of IL-1ra.