The purpose of the invention is to provide: a lactoferrin fusion protein that retains the bioactivity of natural lactoferrin, significantly prolongs the in vivo lifespan, and has better clinical utility than natural lactoferrin and recombinant lactoferrin； and a method for producing the same. The invention provides a fusion protein of: a protein or peptide containing an FcRn binding region； and lactoferrin or a lactoferrin bioactive fragment or peptide； wherein the fusion protein is represented by (LF-s-Y)n or (Y-s-LF)n (in the formula, LF represents lactoferrin or a lactoferrin bioactive fragment or peptide； Y represents a protein or peptide containing an FcRn binding region； s represents a sequence of any 0-10 amino acids； and n represents an integer of 1-10), or a variant thereof.
