Bacillus natt belonged to Bacillus, Bacillaceae, as a kind of probiotic could be used in medicine, food and feed. Astragalus polysaccharide (APS), as an important natural ingredients, were consist with glucose, galactose, arabinose, and so on. Studies results showed that Bacillus natto and APS played a role in enhancing animal immunity, improving animal performance, and promotting the role of feeding effect. A large number of domestic and foreign literatures were readed, the application of Bacillus natto and APS in animal production were revi...