Abstract: Compared with Soxhlet method, microwave extraction of the seed of passionflower is a rapid method (about 120 seconds) with less solvent consumption (about 50mL), higher yield and better oil with good color and odor. A reconstructed home microwave oven is used as the main equipment. The effects of extraction conditions are studied, the optimum process conditions have been worked out and the preliminary study on the basic principle of microwave extraction of significant components from plants is given. The results show that the higher the dielectric constant of solvent, the less the yield is. When hexane is mixed with equal volume acetone, the yield decreases sharply, which is the same as cyclo hexane mixed with dichloromethane. All this infers that nonpolar solvent is fit for microwave extraction of materials containing water. Three material treatments are discussed, and the method of dipping the sample in water for about 24 hours before experiment gives the best result. Data indicate that the higher water content in the seed of passionflower, the more the yield is. Data also show that the effect of continuous radiatioin time under the condition of the same total radiation time is different for linoleic acid and linolenic acid which are the significant components of the product.