Abstract: The combined forms and distribution of selenium,the extraction and separation technology of macromolecule containing selenium in water chestnut of Enshi city were studied. With various extraction solvent polysaccharide and protein of water chestnut was extracted, and the selenium content of all components were determinated by atomic absorption spectrometer. The results were as following: the selenium in protein as the main storing form in the water chestnut accounting for 50.45% of total selenium, and the selenium in alcohol-soluble protein accounting for 38.66%. Also part of selenium and the polysaccharide union are contained.

Key words: water chestnut, selenium in protein, selenium in polysaccharide, combined form