Disclosed herein is a hair care cosmetic which contains an organopolysiloxane defined in following (i) or (ii): (i) an organopolysiloxane in which the organopolysiloxane segment constituting the backbone has the substituent group represented by the following formula (1) which is connected to at least one silicon atom in the segment; wherein Z is an organic group represented by the following formula (2); (ii) an organopolysiloxane in which the organopolysiloxane segment constituting the backbone has the substituent group represented by the following formula (1′) and the substituent group represented by the following formula (3) which are connected to separate silicon atoms in the segment; —X—NH—Z   (1′) wherein Z is an organic group represented by the following formula (2).