Xylooligosaccharides is a kindof functionaloligosaccharides with 2~7 xylose molecules linked byβ–1,4 glycosidic bonds. Becauseof its significant functional properties,such as lowcaloric value,good stability,promoting the multiplicationof bifidobacteria in intestines,inhibiting pathogenic bacteria and soon,xylooligosaccharides has been widely studied and used as a new additive in recent years. It has become a hot spot to develop functional xylooligosaccharide products in foodstuff and feed industries. The main functional properties as well as the applied research and the product development in food,feed,medicine and agriculture fields were introduced in the paper,in addition,the prospect and development trendof xylooligosaccharides were evaluated.