Experimental evidence has been presented to suggest that the human augmenter of liver regeneration (hALR)serves as a hepatotrophic growth factor during liver regeneration and as a generalized growth factor during pancreas transplant/regeneration. A prokaryotic expression plasmid, pRSET/6his-c-myc-hALR was constructed, by cloning synthesized hALR cDNA into pRSET/6his-c-myc that was improved on the basis of pRSET B by the group. As a result, the protein was highly expressed in E. coli BL21. The recombinant hALR was over 60% of the total protein in E. coli. Its validity was confirmed by meansof Western Blotting. The protein was purified by Ni-NTA affinity chromatography and this FAD-dependent sulfhydryl oxidase activity was measured.