Abstract: The ift gene without signal peptide sequence was cloned through PCR and ligated with the expression vector pPIC9K of P.Pichia, resulting in the recombinant plasmid pPIC9K-IFTase.The recombinant plasmid was then linearized and transformed into P.pastoris GS115, and a hight copy recombinant strain of yeast was acquired through concentration gradient resistance screening of G418, and PCR identification method.Using methanol induction for 60h, the recombinant strain P.pastoris secreated IFTase having an activity of 10.3U/mL.This finding indicated that Eukaryotic secretory expression of the IFTase could be performed in P.pastoris.