The present invention provides a cosmetic for hair in which smooth combability without a frictional sensation during cleansing and applying to hair, namely during wetting, the aforementioned effects are not lost by a rinsing operation, smooth combability during and after drying the hair is exhibited, a moisturizing feeling on touch is exhibited without stickiness, and a flexible styling sensation is provided to the hair. A co-modified organopolysiloxane having both a specified hydrophilic group and a siloxane dendron structure-containing group is blended in a cosmetic for hair as an essential component.