To control moromi -mash fermentation process, rapid measurement of glucose concentration is needed.We made a comparative study on four methods measuring glucose contents.Glucose concentrations determined on-line by the hydrogen peroxide electrode as a sensor showed good correlation (0.977 correlation coefficient) with those determined off-line by the glucostat method, when moromi -mash samples were filtered by a 20μm pore-sized filter and a 0.45 μm pore-sized filter successively.On the other hand, among off-line determinations, 0.986 to 0.972 correlation coefficients were obtained between glucose concentrations determined by the medical instruments with the disposable sensors and those determined by the glucostat method, when moromi -mash samples were filtered, and their glucose concentrations were made to be in the range from 4 mg glucose per m l moromi to 40 mg per m l with water.We think that rapid and easy measurement of glucose concentrations in moromi -mash is possible by use of the medical instruments.