Objectives:To express soluble recombinant human keratinocyte growth factor-1(rhKGF-1) in Escherichia coli and determine the bioactivity of rhKGF-1 to provide the basis for developing new drugs containing rhKGF-1. Methods:The sequence encoding ΔN23 rhKGF-1（the form of KGF-1 missing 23amino acids in N terminal） was synthesized and fused with SUMO through overlap PCR to obtain 6His-sumo-rhKGF-1 fusion gene，which was the subcloned into expression plasmid pET30a.The recombinant plasmid pET30a-6His-sumo-rhKGF-1 was then transfected to E.coli BL21(DE3) for expressing the fusion protein. Firstly ,the fusion protein was purified by Ni-NTA.Then,it was digested by Sumo Protease,and purified by Ni-NTA again to obtain purified ΔN23 rhKGF1. The ΔN23 rhKGF1 was used to promote proliferation of HaCat cells,then assay its bioactivity by CCK-8 methods.Results:Recombiant expression plasmid pET30a-6His-sumo-rhKGF1 was constructed correctly,the result of sequencing was the same as the expected.The fusion protein was expressed in E.coli BL21(DE3) in soluble form.After purification and SUMO Protease digestion,purified ΔN23 rhKGF-1 had been obtained.It could promote HaCat cells proliferation,the value of EC₅₀ was 6.11ng/mL.