ABSTRACTS 207 Phase inversion temperature (PIT) emulsification is the method which use the change of the balance for hydrophilic-hydrophobic of nonionic surface active agent. In this study emulsions were assembled ac- cording to PIT emulsification with POE (n) sorbitol tetraoleate (n: 30, 60) and POE (20) hydrogenated castor oil as emulsifier, and were subjected to evalu- ation of particle size and storage stability. Thus in order to obtain ultra fine emulsion with less than 200 nm in diameter, the combination of emulsifier and oil is important. Stability of ultra fine emulsion prepared with POE (20) hydrogenated castor oil was good on the other hand prepared with POE (n) sorbitol tetraoleate (n: 30, 60) depended on oils. We could obtain ultra fine and stable emulsion with mixture of the emulsifiers for various oils. Key words: phase inversion temperature, emulsifi- cation, ultrafine emulsion, POE (30) sorbitol tetra- oleate, POE (60) sorbitol tetraoleate, POE (20) hy- drogenated castor oil, particle size, storage stability, emulsifier, oil