Bacillus natto was the primary microorganism used in the production of natto,and the study on the characterization of protease from Bacillus natto will help to conduct the production of natto and to explore new protease.One Bacillus natto of high-yield protease was isolated from natto,and catalysis characterization of protease secreted from this Bacillus natto was investigated.Results indicated: protease from Bacillus natto was a particular Metalloproteases,it could be completely inhibited by EDTA,and had Ca2+ in the active center.The protease had the maximum activity at pH 7.0 and 60℃ and was stable in the pH range of 6.0~9.0 and below 45℃.The protease was unstable at 50℃and the kinetics of deactivation fit the model: a=0.124+0.887e(-0.45t).Protease from Bacillus natto has a very high hydrolysis efficiency to soy protein,meaning that it's a good application in the production of hydrolysate of food protein.