Abstract: Xylo-oligosaccharide is a new type of feed additive and it has functions of promoting the proliferation of intestinal beneficial bacteria,adsorbing intestinal pathogen,enhancing the body immunity,promoting the lipid metabolism,mineral metabolism and antioxidant,etc..The application of xylo-oligosaccharide as feed additive in the feed industry has been confirmed.And xylo-oligosaccharide has been widely used in the feed of pig,poultry,ruminant and aquatic animals.The research results validated that xylo-oligosaccharide could improve the production performance of animals,improve the body immunity and disease resistance of animals.And adding xylo-oligosaccharide can also reduce drug dosage in feed and decrease the drug residues,which was helpful for environmental protection.The chemical structure,physicochemical properties and mechanism of xylo-oligosaccharide and its application effect in the production of animal husbandry were mainly introduced.And its prospects were predicted.