One of the purposes of the present invention is to provide an aqueous dispersion of silicone elastomer particles to provide a stable emulsion and the silicone elastomer particle, wherein a polyoxyethylene alkyl ether which has an alkyl group having a large number of carbon atoms is used as a surfactant. Further, another purpose is to provide a cosmetic comprising said aqueous dispersion or said silicone elastomer particles and giving a good feeling in the use. The present invention provides an aqueous dispersion comprising (A) silicone elastomer particles having a 90% volume cumulative diameter (D90) of 0.3 to 20 μm in an amount of 5 to 80 mass %, based on a total mass of the aqueous dispersion, (B) at least one polyoxyethylene alkyl ether having an alkyl group having 18 carbon atoms in an amount of 0.01 to 15 mass %, based on a total mass of the aqueous dispersion, wherein a hydrophile-lipophile balance (HLB) of the polyoxyethylene alkyl ether is 12.8 to 15.1, and (C) water in an amount of 19 to 94 mass %, based on a total mass of the aqueous dispersion. Further, the present invention provides a material comprising the aforesaid components (A) and (B), a method for preparing the material and a cosmetic comprising the aqueous dispersion or the material.