Abstract: The main nutrients were measured to study the main component of the fermented natto and compare the nutrition components of natto and bacillus natto prepration with the soybean powder,the changes of main components were explored during the fermentation process. The results showed that compared with soybean powder,ash and amino acid nitrogen content in natto lyophilization powder(NLP) were increased significantly(p<0.05). The crude fiber,crude fat,moisture content in NLP decreased significantly(p<0.05). Compared with liquid culture product of bacillus natto, the crude protein content in bacillus natto preparation( BNPr) was extremely increased significantly( p <0.01), while the ash and amino acid nitrogen content were increased significantly(p<0.05). The moisture content was decreased extremely significantly(p<0.01) and the crude fiber content was decreased significantly(p<0.05). In addition, after fermentation, the natto kinase content in BNPr and NLP increased, and the soybean isoflavone and phytic acid content in NLP were decreased extremely significantly(p <0.01),and vitamin K2 content significantly decreased(p <0.05). The experiment proved that BNPr and NLP had higher nutritional value than soybean powder.