Abstract A fungus, SM-30 was isolated as using triglyceride and hardly using oleate, and identified as a member of the genus Trichoderma. In the culture fluid of the organism, the presence of triglyceride-binding proteins (TG-proteins) was demonstrated by an over-lay method; two TG-proteins with molecular weights (MWs) of 24 and 8 kDs (10 3 daltons) in the culture of soybean oil medium, while in the culture of glucose medium, only one TG-protein (MW 8 kD) was found. These proteins were purified and their biochemical and physicochemical properties were studied. All of them showed affinities to a triglyceride (triolein) and triglyceride-emulsion-stabilizing activities without any lipase activity. The comparison of the emulsion-stabilizing activities in the three culture fractions, such as extracellular (culture fluid), cell-membranous (cell envelope), and intracellular (cytoplasm) fractions, indicated that the gradient of the stabilizing activity in the culture is intracellular-high and extracellular-low. Subsequently, the entry flow of triglyceride in the fungus might be superior in speed to the exit flow.