An amino acid-modified organopolysiloxane is provided. It has an amino acid derivative bonded to at least one silicon atom of the organopolysiloxane segment constituting the backbone of the organopolysiloxane via an amide bond represented by the following general formula (1): wherein X and Y are independently a C1-10 divalent hydrocarbon group; m is an integer of 0 to 4; Ra is hydrogen atom, a monovalent hydrocarbon group containing 1 to 4 carbon atoms, or an organic group represented by the following general formula (2): (wherein Rb is hydrogen atom, a C1-7 monovalent hydrocarbon group, an alkaline metal, or an alkaline earth metal, and Rc is independently hydrogen atom, hydroxy group, or a C1-10 monovalent hydrocarbon group optionally containing oxygen atom, sulfur atom, or nitrogen atom); and Z is an organic group represented by the general formula (2).