Objective To study the preparation of Fructus perrillae oil nanoemulsion and its quality evaluation. Methods The formulations of Fructus Perrillae oil nanoemulsion were optimized by drawing the pseudoternary phase diagrams and investigating the form, viscosity, particle size distribution, stability, conductance, and refractiratio. Results The optimal formulation was composed of wheat oil and cremophor RH40, electron microscopy presented Fructus Perrillae oil nanoemulsion as small spherical drops, viscosity was (5.49?0.02)/mm2?s-1, conductance was 316/ms-1, refractiratio was (1.124?0.002 50), and mean diameter of particle was (50.3?1.1) nm.The average recovery determined by GC was 98.9%, its mean RSD was 0.88%. Conclusion The solubility and stability of Fructus Perrillae oil are promoted by nanoemulsion with better produncibility. It is a favorable medical matrix.