Abstract: The selenide taraxacum polysaccharide was prepared by using taraxacum polysaccharide and sodium selenite as the raw material, according to the synthesis principe of organic selenium compound. The optimal conditions were established by single factor and orthogonal design, the content of polysaccharide selenide was determined by HPLC, the structure of polysaccharide selenide were characterized by IR and DSC. The results showed that the mass ratio of taraxacum polysaccharide to sodium selenite was 1 ∶1.2, the volume fraction of HNO3 was 0.3%, the reaction temperature was 70℃ and the reaction time was 8 hours.Under the conditions, the average content of selenium in taraxacum polysaccharide was 3.79mg/g and average yield was 33.58%. Infrared Spectrum showed that the selenide taraxacum polysaccharide contained Se=O and Se-C, the selenization of taraxacum polysaccharide was realized, which provide a good condition for further development and utilization.