Abstract: The impact of monoglyceride addition on interface emulsifier concentration, protein concentration in liquid phase, particle size distribution, partial coalescence of fat and centrifugal creaming ratio in a model emulsion stabilized by casein were studied. The possible mechanisms were also revealed. The result showed that with the addition of monoglycerides increasing, the competitive absorption of monoglyceride on the interface membrane enhanced, both interface monoglyceride concentration and protein concentration in liquid phase gradually increased. The surface area mean diameter (D (3, 2) ) , volume mean diameter (D (4, 3) ) , the partial coalescence of fat and the centrifugal creaming ratio decreased first and increased later, whose minimums appeared when the amount of monoglyceride was 0.6%, indicating that the emulsion was most stable.