Objective:The study aimed to research the characterization, rheological properties and antioxidant activities of polysaccharide from Azolla.Methods:The polysaccharide was obtained through hot water extraction. The molecular weight, monosaccharide composition, microstructure, rheological properties and antioxidant activities were analyzed by gel-permeation chromatography (GPC), FT-IR spectrometric, scanning electron microscopy (SEM) and so on.Results:The polysaccharide from Azolla containing two groups of molecular weight (2 338.00 and 1.60 kDa) was an acidic heteropolysaccharide, which was mainly composed of mannose, glucuronic acid, galactose, xylose and glucose. The sample had the typical absorption peaks of polysaccharide, which connection mode of heterocephalic carbon was β-configuration. The micro level presented the network structure, and the molecules mainly existed in the form of flexible chains. The polysaccharide solution was the pseudoplastic fluid with shear thinning and had weak gel properties. The IC50 values of polysaccharide from Azolla for DPPH radical, ABTS radical and hydroxyl radical were 0.32, 1.00 and 0.96 mg/mL respectively.Conclusion:Polysaccharide from Azolla had good rheological properties and potential antioxidant activities.