Abstract: Nano-selenium (Selenium nanoparticles, SeNPs) has unique properties and potential applications in the fields of food, medicine, pharmacology and agriculture. Polysaccharide is a natural biopolymer, which is considered to be the most promising carrier for the synthesis of SeNPs due to its excellent biocompatibility and biodegradability. This article summarizes the research progress in the synthesis of SeNPs using polysaccharides as templates. The effects of different types of polysaccharides and different synthesis conditions on the properties of polysaccharide-selenium nanoparticles composites are also discussed. Finally, the applications of these composites in anti-tumor are introduced, which provides new ideas in constructing SeNPs system using polysaccharides as carriers and further promotes their applications in the fields of medicine and food.