A novel spontaneous emulsification method using porous polymer particles was investigated for the facile preparation of emulsions without mechanical manipulation. Porous water-soluble polymer particles prepared by spray freeze-drying could absorb soybean oil via capillary action. When the particles were added to water, emulsification proceeded rapidly with the dissolution of the polymer. The importance of using a water-soluble polymer for particle formation for the formation of fine emulsions and maintenance of dispersibility was confirmed. This emulsification technology is expected to be applied to the development of formulations that improve the solubility and mucosal absorption of poorly water-soluble drugs.