In this experiment, the surface-active substances were extracted from defatted rice bran and their emulsifying properties were investigated. The sample emulsions stabilized with the surface-active substances (3 fractions: 1-HS, 6-HS and 18-HS) were prepared and then their physico-chemical properties such as fat globule size, creaming stability, oil-off and dispersion stability were determined. It was found that sample emulsion with different fraction of surface-active substances showed different physico-chemical properties from each other. Specially, 1-HS emulsion with the smallest particle size was evaluated to be superior to others in terms of higher creaming stability, low incidence of oil-off and higher dispersion stability. From the study of co-surfactant addition (Tween 20, SSL and GMS), GMS was found to be the most effective in reducing fat globule size in 1-HS emulsion. This indicated that there might be a co-operative adsorption of the two surface-active substances at the oil-water interface. Thus, the potentiality of the rice bran extracts, obtained with specific conditions, as natural surface-active substances was confirmed.