The research of oligosaccharides chains and function are important directions of glycobiology research in the future,which will bring new hope to the research and treatment of human diseases.With deep research on carbohydrates,oligosaccharide have attracted extensive attention of scholars at home and abroad in recent years because of their various pharmacological activities.The structure of oligosaccharide is complex and diverse influenced by linkage site,sugar ring structure and branch,which bring great challenges to its extraction,purification,separation analysis and structural characterization.This article summarized domestic and foreign researches on extraction,purification,separation and analysis,and structural characterization of traditional Chinese medicine on oligosaccharides in recent years,and in order to provide a reference for modern drugs research,clinical applications of oligosaccharides and the creation of functional products.