Abstract: Polysaccharides are a class of natural macromolecular polymers with complex and large molecular structures, which are closely related to their biological activities. However, traditional analytical methods can only provide limited information on the structures of polysaccharides. Mass spectrometry (MS) is an analytical method that measures the mass-to-charge ratio of molecules allowing for determination of the mass and calculation of the the molecular structure. As a powerful tool for polysaccharide structure analysis, MS can provide rich information, including molecular mass, polymerization degree, monosaccharide composition, glycosidic bond type, the order of arrangement of glycosyl groups, and substituent group sites, which has unique advantages in the characterization of polysaccharide structure. This paper summarizes the general pattern of mass spectral fragmentation of polysaccharides, introduces the principles and characteristics of different types of MS as well as representative applications of MS combined with electron ionization source, fast atom bombardment source, electrospray ionization source, matrix-assisted laser desorption ion source, real-time direct analysis source, ion mobility or tandem mass spectrometry for the structural elucidation of polysaccharides. Furthermore, future prospects for the application of new MS techniques for analyzing the structures of polysaccharides are discussed. The aim of this paper is to summarize the application of MS to provide scientific reference for the basic research work of polysaccharide compounds, such as quality standard, structural characterization, pharmacodynamics, pharmacokinetic, constitutive relationship, and the development and creation of polysaccharide food, health food, and clinical drugs.

Key words: polysaccharide; mass spectrometry; structure; analysis; application