in this work, the phase structure type of core-forming component in a series of SEBS/PA-6/SAN ternary blends showing core-shell morphology was investigated. In this way, influence of the elasticity and viscosity of ternary blend components, thermodynamic and kinetic factors were considered. Scanning electron microscope was used to study the morphology of ternary blends as well as internal phase structure of core-forming polymer. All prepared ternary blends showed core-shell morphology, in which the multiple small droplets of PA6 were surrounded by SAN shell layer within SEBS matrix. It was demonstrated that elasticity plays a more leading role in the evolution of morphology of ternary polymer blends compared to the viscosity.