Abstract: In order to improve the availability of perilla oil, the influences of surfactant, organic acid, temperature and NaCl concentration on the microemulsion region of perilla oil were investigated by pseudo-ternary phase diagrams.The conductivity and particle size of the oil-in-water microemulsion were also determined.The results showed that a large oil-in-water microemulsion region of perilla oil was obtained in the presence of Tween-80 and salicylic acid at 25℃.Low NaCl concentration favored the water solubilization.However, excessive NaCl could decrease the microemulsion region.According to the conductivity, the microemulsion could be divided into water in oil (W/O), bicontinuous (BC) and oil in water (O/W) regions.The particle size of oil-in-water microemulsion was 10 to 100 nm, and decreased gradually with the increase of water content.The food-grade perilla oil microemulsion was prepared conveniently and had high stability, and could improve utilization rate of perilla oil.