Following seven compounds were tested as to their antiseptic actions against soy sauce: m-Nitrocinnamic acid, ethyl p-nitrocinnamate, m-aminocinnamic acid hydrochloride, p-hydroxycinnamic acid, phthalidene-acetic acid, phthalimidene-acetic acid, and methylene-phthalimidine. These were found to have almost no antiseptic acitivities at the concentration of 0.001-0.01%.