A study is presented of the optical order parameters and spectroscopic properties of I-amino-4-hydroxyanthraquinone derivatives containing various substituents in the 2-position in a nematic liquid crystalline mixture composed of cyanophenylcyclohexane derivatives. The results are discussed in terms of the effects of the dye structure on the order parameters. By introducing a-SCH2-group into the 2-position, magenta dyes have been obtained which show high order parameters and solubilities. In addition, preliminary data on the solubility and photostability of the dyes are reported.