Abstract: Objective To study the relationship between the C-terminal structure of hHSF and its chemotaxis activity. Methods The artificial DNA fragments encoding three C terminal truncated hHSF analogs were obtained by PCR,then cloned into the vector pET30a or pET42a,recpectivelly,and expressed in E.coli BL21（DE3）with IPTG induction,subsequently.hHSF1-66 and hHSF1-59 were purified by gel filtration and cation exchange chromatography and subjected to refolding. hHSF1-53 was purified by affinity gel chromatography, EK cleavage,and gel filtration. The molecular weight of three hHSF analogs and its immunity were measured by MALDI-TOF Mass Spectroscopy and Western blot respectivelly. The chemotaxis activity of hHSF and its mutants for human neutroplil was detected by Boyden chamber method with modification. Results The sequences of hHSF1-66,hHSF1-59 and hHSF1-53 were correct as shown by gene sequencing. The expression level of hHSF1-66 and hHSF1-59 was about 20% of total cell proteins,which is major in inclusion bodies form. The yield of fusion protein GST-hHSF1-53 is over 30% of total cell proteins, most of which is soluble.The purifity of target proteins was over 95%. The molecular weight of hHSF1-66,hHSF1-59 and hHSF1-53 was 7206.0,6401.2 and 5697.3,respectively and had hHSF immuno-activity. In comparison with the full length hHSF,the maxium chemotaxis activity(50nmol/L) of hHSF1-66 (less 3 residues) and hHSF for their ability to stimulate human PMN was no significantly difference . But the maxium chemataxis activity of hHSF1-59 (less 10 residues) and hHSF1-53 (less 16 residues,α-helix) was decreased 34.3% and 70.5% ,respectively. Conclusion The α-helix at C-terminus of hHSF is important for the stabilization of its molecular stereo-conformation.