Oligosaccharides, especially the glycans on the glycoconjugates, play important roles in the cell recognition, signal transduction and receptor modulation phenomena in the life processes. The application of new techniques such as HPLC, capillary electrophoresis, MS, NMR, fluorophore-assisted carbohydrate electrophoresis and reagent array analysis method, allows the isolation and structural determination of oligosaccharide more rapid, convenient and accurate. Also it is now possible to understand more complete the structure-function relationship of the trace oligosaccharide, while a variety of powerful tools are combined.