Abstract: Whey protein concentrate and OSA modified starch were selected as wall material,hydrogenated palm oil and high oleic sunflower oil as core material.The effect of p H and homogeneous pressure on emulsion stability and oxidation stability were investigated.The results showed that the mean emulsion droplet size was at the minimum value under neutral p H condition while the absolute value of Zeta potential reached at 42 m V. The emulsification system owned a certain static stability under neutral p H condition.The optimal homogeneous condition was 35 MPa twice and the mean emulsion droplet size could maintain at 400 nm.Emulsion homogenized twice showed superior stability.As the extension of storage time,the oxidative degree of hydrogenated palm oil was higher than high oleic sunflower oil. Encapsulation can help high content of unsaturated fatty acid core oil from oxidation in a certain extent.