Objective:To express the soluble recombinant hemangiopoietin protein in E.coli BL21（DE3）.Methods:Using human fetal live cDNA as a template

a partial cDNA fragment of HAPO coding N-terminal region was subcloned into plasmids pTrc99

pQE60 and pET32c to construct different recombinant prokaryotic expression systems.After selecting

the soluble rhHAPO fusion protein was expressed stably in E.coli BL21（DE3） by vector pET32c-HAPO and further isolated by nickelnitrilotriacetic acid（NTA） affinity chromatography.After cleavage with enterokinase

the rhHAPO protein was applied to Fast Flow SP sepharose column.Results:The rhHAPO protein had a purity of more than 95% and a good bioactivity based on the cell adhesion assay in ECV304 cells.Conclusion:We have established a protein engineering system to produce rhHAPO which may provide the possibility for clinical application.