The present disclosure relates to a cosmetic composition comprising, in a cosmetically acceptable medium, at least one dispersion of polymer particles in a liquid silicone medium, the polymer being a copolymer comprising at least one first block that is soluble and at least one second block that is insoluble in the silicone medium.Another aspect of the present disclosure relates to a dispersion of polymer particles in a liquid silicone medium, and also to a cosmetic process for making up, cleansing, protecting against the sun, shaping, dyeing or caring for keratin materials, such as the body or facial skin, the nails, the hair and/or the eyelashes, and for use with the present composition.