Objective This paper aims to characterize the composition and structure of two polysaccharides extracted from Noni fruit and compare their in vitro hypoglycaemic and hypolipidemic activities.Methods Two polysaccharides, NFP-30 and NFP-80, were extracted and isolated from Noni fruit by water extraction and ethanol precipitation method. They were then characterized by means of physicochemical analyses, spectral analyses, and scanning electron microscopy observations, and their in vitro hypoglycaemic and hypolipidemic activities were evaluated by the determination of the inhibition rates of α-glucosidase and pancreatic lipase.Results The neutral sugar contents of NFP-30 and NFP-80 were (50.73±1.32)% and (42.30±1.11)%, respectively, and the glucuronic acid contents were (61.48±0.40)% and (27.05±0.28)%, respectively, which indicated that both of them were acidic polysaccharides. When passing through the DEAE-52 chromatographic column, both polysaccharides had a main peak at the NaCl concentration of 0.9 mol/L, indicating that the components of both polysaccharides were relatively concentrated. In terms of the maximum inhibition rate of α-glucosidase, NFP-30 reached 58.45%, while NFP-80 only had 0.21%. In terms of the maximum inhibition rate of pancreatic lipase, NFP-30 reached 34.63%, while NFP-80 only had 9.77%, and the inhibition rate of NFP-80 on the activities of the two enzymes was significantly lower than that of NFP-30.Conclusion The neutral sugar content and glucuronic acid content of NFP-30 are higher than those of NFP-80, and its in vitro hypoglycaemic and hypolipidemic activities are better than those of NFP-80.