An object of the present invention is to provide a method of easily producing fine particles comprising a lipid, a fatty acid, or a derivative thereof, surface-modified with a water-soluble substance, etc. There are provided a method of producing a fine particles, surface-modified with a water-soluble substance, which contains the process of dispersing fine particles comprising a lipid, a fatty acid, or a derivative thereof, and dissolving or dispersing a surface modifier which is a lipid derivative, a fatty acid derivative, or an aliphatic hydrocarbon derivative of a water-soluble substance, in a liquid containing a polar organic solvent, and the like.
