Animal derived antimicrobial peptides are effector molecules of the innate immune system,with its characteristics including broad spectrum antimicrobial activity,reduced side effects and drug resistance,and it has been w idely attracted and considered as the best alternative to antibiotics. Large amounts of researches have proved that antimicrobial peptides not only have anti-bacterial,anti-viral,anti-fungal,anti-tumor effects,but also exert functions as anti-inflammatory,leukocyte recruitment,w ound repairing and epithelial barrier protection. Some peptides even have synergistic effect w ith antibiotics. Because of limited sources of natural antimicrobial peptides and high cost of chemical synthesis,recombinant expression of antimicrobial peptides may be the most efficient w ay to get antimicrobial peptides. Besides,other studies show ed that nutritional regulation w as an effective w ay to induce the expression of antimicrobial peptides. How ever,the w ay to apply antimicrobial peptides in the livestock industry still has been facing many problems,and one is its production; the other is its stability and absorption in vivo. This paper review ed the biological function and underlying mechanism,stability,developmental expression pattern,molecular design and recombinant expression strategies of animalderived antimicrobial peptides,w ith a goal to provide important information for the development of new,efficient and environmental friendly antibiotic alternatives.