The present invention provides a lactoferrin fusion protein having highclinicalutility and a production method therefor. The present invention furtherprovides: alactoferrin fusion protein that retains the biological activity of nativelactoferrin whilehaving a significantly extended in vivo life span, and that has more clinicalutility thannative lactoferrin and recombinant lactoferrin； and a production methodtherefor. Withthis fusion protein or a variant thereof, the ability of lactoferrin to bindiron is retained,and therefore at least the important biological activity of lactoferrin thatis based on theiron-binding ability is retained. Additionally, this fusion protein or variantthereof hasbioavailability and resistance to protease, and thus can exhibit biologicalactivity in vivoover a long period. Furthermore, this fusion protein is not easily broken downbypepsin in the stomach.
