Screening tests were undertaken to obtain microorganisms which produce myrosinase. One strain of microorganism indicated a strong capasity for producing myrosinase. The morphological and physiological characteristics of this strain were studied. The organism was identified as Enterobacter cloacae, no. 506.Enzyme production was induced by the addition of 0.01% sinigrin and 6% mustard extract*2 to the culture medium. The highest production was obtained after 36~40 hr cultivation when the strain was cultivated at 28°C in a medium containing 0.01% sinigrin, 6% Mustard ext., 0.1% KH2PO4, 0.1% NH4Cl, 0.1% NaCl and 0.1% MgSO4·7aq, (pH 7.0).