To remarkably efficiently and simply produce a small diameter of a complete round spherical microcapsule with small temp. restriction by emulsifying an oily component in the presence of a water soluble aligning acid or the like and producing the microcapsule by an interfacially polymerizing method.

A microcapsule wall is formed by adding the oily component containing a reaction compound of a reaction pair into a water phase prepared by adding a reaction compound for forming the microcapsule wall and a dispersion stabilizer into water to emulsify and allowing the water phase to interfacially react with the oil phase. At this time, as the dispersion stabilizer, alginic acid or its derivative such as ethylene glycol alginate is used. The oil component consists of a material to be encapsulated such as a wax and a compound reacting with the compound such as an isocyanate compound in the water phase at the time of forming the wall. By the presence of the water soluble alginic acid in this way, the complete round spherical capsule having small particle diameter is produced and the complete covering property is abtd.