Natto is a Japanese traditional food made from whole soybenas by fermentation of Bacillus natto. This study was attempted to improve the taste of Natto. Natto was compared with the changes in the various chemical properties after it had been produced by the addition of garlic and red pepper oleoresin. the remained content of total sugar fo Natto added with red pepper oleoresin decreased than other groups during 24hours fermentation. The remained content of reduced sugar of Natto added with garlic, red pepper oleoresin increased than other groups. The amount of total free sugar showed almost no differences in the case of garlic and red pepper oleoresin added. Amino type nitrogen content increased gradually after 24 hour fermentation in all samples. Free amino acid content increased in conventinal Natto.