Objective:To obtain the functional single chain Fv antibody(scFv) against acidic isoferritin(AIF).Methods:An expression vector pPOW4c9 was constructed by subcloning AIF4c9 scFv gene into a heat-inducible bacterial expression plasmid pPOW3. Then recombinant vector was introduced into E.coli DH5? by electro-transformation. The soluble expression was performed by temperature induction. After purified by the Ni-chelating chromatography, the recombinant anti-AIF scFv was characterized.Results:Soluble expression of the scFv in E. coli was achieved. The yield of purified anti-AIF scFv was 1.6 mg/L. The recombinant protein recognized AIF specifically identified by ELISA and western blotting, and an affinity constant of scFv was 3.18?10~ -8 mol/L.Conclusion:The results indicate that recombinant soluble scFv retains the specific binding activity to AIF.