The objective of the experiment was to study an experimental method which could be applied to test the characteristics of Bacillus natto and to evaluate its feeding value. The experiment mainly focused on the conformation and physiological biochemical characteristics of Bacillus natto, the influence of different temperatures, degree of acidity, bile salts and artificial gastric juice treatment on the survival rate of Bacillus natto, and effects of commonused antibiotics and microelements on its growth. And it was also to evaluate the influences of Bacillus natto on malignant bacteria and some anti-nutritionalfactors. Results showed that Bacillus natto had a capability to resist high temperature, acidity, bile salts and artificial gastric juice, and it could also inhibit E.coli and Staphylococcus aureus. Meanwhile, Bacillus natto could decompose and utilize some anti-nutritionalfactors such as hemicellulose, phytate and pectin. It was concluded that Bacillus natto was an excellent microbial feed additive.