Lactoferrin is a multifunctional glycoprotein that is present in several mucosal secretions. In this study, we exploited the silkworm, Bombyx mori, as host for the recombinant baculovirus harboring the porcine lactoferrin (PLF) gene to produce the recombinant PLF (rPLF). Around 205 mu g of rPLF was purified from a single silk-worm pupa infected by the virus and the rPLF was proved to be biologically active. This method established in our study will pave the way for efficient industrial production of rPLF on a large scale for further utilization of this protein as a feed additive in the future.