There is disclosed an organopolysiloxane represented by the following general formula (1).(each R1 independently represents a group selected from an alkyl group having 1 to 30 carbon atoms, a fluorine-substituted alkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, and an aralkyl group having 6 to 30 carbon atoms; Y represents a polyvalent alcohol compound residue; M represents any of a hydrogen atom, an alkaline metal atom, an ammonium ion, and an alkylammonium ion; and reference character m represents an integer of 0 to 300.) There can be an organopolysiloxane capable of providing a cosmetic having excellent emulsion stability, excellent powder-dispersion stability if powders are contained therein, and excellent skin affinity and cosmetic durability, due to a novel organopolysiloxane having a specific structure containing a nonionic hydrophilic group and an anionic hydrophilic group of a carboxylic acid structure; and a cosmetic containing it.