Houttuynia cordata Thunb (H. cordata) is a medicinal and edible homologous plant. The abundant water-soluble polysaccharides of H. cordatahave been proved to have a variety of biological activities. However， the current research on polysaccharides from H. cordata mainly focuses on the whole plant or aboveground parts. The differences in the structure and activity of polysaccharides from different parts of H. cordataare rarely reported. In this study， the polysaccharides from the rhizome (RHCP)， stem (SHCP) and leaf (LHCP) of H. cordata were extracted and separated， and their structural characterization， antioxidant activity in vitro and α-glucosidase inhibitory activity were determined. The aim was to explore the relationship between the structure and biological activity of H. cordata polysaccharides (HCPs). Results showed that polysaccharides in different parts of H. cordata were acidic polysaccharides， which were composed of glucose， galactose， arabinose， rhamnose， galactose uronic acid， and a small amount of fucose， mannose， xylose， and glucuronic acid， but the proportions are different； The molecular weight was 4.11×104 u to 1.20×106 u； The infrared structure was basically the same； LHCP had higher content of methyl and acetyl groups， and their contents were 0.95% and 1.05% respectively； The surface morphology of the three polysaccharides was smooth and flat； LHCP was not triple helix polysaccharide， while RHCP and SHCP existed triple helical structure. The in vitro antioxidant and α-glucosidase inhibition ability of LHCP were the strongest. It was found that the structure and activity of polysaccharides from different parts of H. cordata were different， providing a theoretical basis for the study of the structure-activity relationship of HCPs and providing a theoretical basis for the development and utilization of HCPs.