Lactoferricin is an amphipathic,cationic peptide with stronger anti-microbial activity than lactoferrin.It was mainly generated by the pepsin-mediated digestion from N-terminal of lactoferrin in small scale,Genetic engineering will be the best method to produce lactoferricin.This paper gives an overview on antimicrobial activities of lactoferricin and its production by genetic engineering including the selection and comparision of expression systems,isolation and purification of lactoferricin from the fermented broth of genetic engineering bacteria.