It is an object of the present invention to provide a dimer diol derivative and a composition containing the dimer diol derivative which have an excellent water-holding property, an excellent pigment dispersion property and further a high level of safety.The dimer diol derivatives according to the present invention is a dimer diol derivative represented by the following chemical formula 19. ##STR00001## (wherein R is a dimer diol residue, X is hydrogen atoms, the following chemical formula 20 or the following chemical formula 21, and Y is hydrogen atoms, the following chemical formula 20 or the following chemical formula 21 (except that a case where both X and Y are hydrogen atoms), ##STR00002## (wherein R.sub.1 is an aliphatic hydrocarbon group having 1 to 22 carbon atoms, Z is the following chemical formula 22 and/or the following chemical formula 23, and n is an integer including zero), ##STR00003## (wherein R.sub.1 is an aliphatic hydrocarbon group having 1 to 22 carbon atoms, Z is the following chemical formula 22 and/or the following chemical formula 23, and n is an integer including zero), ##STR00004## (wherein R.sub.1 is an aliphatic hydrocarbon group having 1 to 22 carbon atoms), ##STR00005## (wherein R.sub.1 is an aliphatic hydrocarbon group having 1 to 22 carbon atoms).