Using natural compounds such as flavonoids in various diseases are under special consideration. Unfortunately poor solubility of flavonoids is an important limitation in preparing pharmaceutical dosage forms. It is reported that preparing nonoparticles can overcome poor solubility problem of the mentioned compounds. The O/ W nano dispersions are a group of preparations in which the poorly soluble drugs could be dissolved in the oil core and/or adsorbed on the O/W interface. Dispersion of flavonoids was prepared by solvent diffusion method in organic phase and lecithine. After adding the dispersion to the aqueous phase, ultrasonication and ultra centrifugation were carried out. A mixture of tween 80 and water were added to the mixture and then ultrasonicated again. Solvent was removed under reduced pressure at 50۫ C using nitrogen-purged vials. The particles were then evaluated for size and size distribution, zeta potential ( ZEN 3000, Malvern, England ), shape, percent entrapment, and in vitro release. Differential scanning calorimetry method was used to understand the thermotropic properties and phase transition behavior. Droplet size of nanoparticles of ferulic acid was 108 ± 12 nm.