A diglycerin derivative-modified silicone, wherein the diglycerin derivative-modified silicone contains a long chain alkyl group as a lipophilic group in a molecule, does not have an oxyalkylene structure wherein an average value of the number of repetitions of the oxyalkylene unit is two or more, has only a glycerin derivative group with an average value of the number of repetitions of glycerin units of 1.1 to 2.9 as a hydrophilic group, and does not have other hydrophilic group in the molecule； a surfactant and dispersing agent, an emulsifier for a water-in-oil emulsion, an external use preparation, and a cosmetic composition containing the same.
