Abstract: To study the drying mechanism of droplet/particle in spray drying process,the gum arabic/whey protein-encapsulated emulsions were prepared and single droplet drying(SDD)was been proposed that can simulate the environment of spray-drying. The effects of drying air temperatures and types of wall materials on the drying behavior of droplet/particle and the generated particle properties were studied by analyzing the drying process of droplet/particles. The results showed that the generated particle was the largest at drying air temperature of 130 ℃,followed by 110 ℃,while the generated particle was the smallest at 90 ℃. At high drying air temperature the earlier formation of crust prevents the particle from shrinking inward. In addition,the increasing of drying air temperature can improve the drying rate of droplets/particles. Compared with gum arabic-encapsulated emulsion,the generated particle of whey protein-encapsulated emulsion drople which deceleration phase arrive earlier has smaller shrink rate. The results indicated that the dry air temperature and the types of wall materials have a significant effect on shell formation behavior and morphology of generated particles.